Number of the day: 7824

Sophie Germain was born on this day 241 years ago.

Alexander Craig Aitken was born on this day 122 years ago.

Properties of the number 7824:

7824 = 2⁴ × 3 × 163 is the 6834^th composite number and is not squarefree.
7824 has 3 distinct prime factors, 20 divisors, 3 antidivisors and 2592 totatives.
7824 has a semiprime digit sum 21 in base 10.
7824 has a Fibonacci digit sum 21 in base 10.
7824 has a triangular digit sum 21 in base 10.
Reversing the decimal digits of 7824 results in a semiprime.
7824 = 1957² - 1955² = 980² - 976² = 655² - 649² = 493² - 485² = 332² - 320² = 175² - 151² is the difference of 2 nonnegative squares in 6 ways.
7824 is the difference of 2 positive pentagonal numbers in 1 way.
7824 = 4² + 8² + 88² is the sum of 3 positive squares.
7824² is the sum of 3 positive squares.
7824 is a divisor of 977² - 1.
7824 is palindromic in (at least) base -46.
7824 in base 5 = 222244 and consists of only the digits '2' and '4'.
7824 in base 25 = cco and consists of only the digits 'c' and 'o'.
7824 in base 39 = 55O and consists of only the digits '5' and 'O'.
7824 in base 62 = 22C and consists of only the digits '2' and 'C'.

The number 7824 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A067153: Number of regions in regular n-gon which are hexagons.
A073118: Total sum of prime parts in all partitions of n.
A087316: a(n) = Sum_{k=1..n} prime(k)^prime(n-k+1).
A128129: Expansion of (chi(-q^3)/ chi^3(-q) -1)/3 in powers of q where chi() is a Ramanujan theta function.
A132975: Expansion of q * psi(-q^9) / psi(-q) in powers of q where psi() is a Ramanujan theta function.
A132977: Expansion of q^(-1/3) * (eta(q^6)^4 / (eta(q) * eta(q^3) * eta(q^4) * eta(q^12)))^2 in powers of q.
A152760: 4 times 9-gonal numbers: a(n) = 2*n*(7*n-5).
A182977: Total number of parts that are neither the smallest part nor the largest part in all partitions of n.
A194560: G.f.: Sum_{n>=1} G_n(x)^n where G_n(x) = x + x*G_n(x)^n.
A204432: Permanent of the n-th principal submatrix of A204431.