Properties of the number 661057:
661057 is a cyclic number.661057 = 61 × 10837 is semiprime and squarefree.
661057 has 2 distinct prime factors, 4 divisors, 19 antidivisors and 650160 totatives.
661057 has a semiprime digit sum 25 in base 10.
Reversing the decimal digits of 661057 results in an emirpimes.
661057 = 3305292 - 3305282 = 54492 - 53882 is the difference of 2 nonnegative squares in 2 ways.
661057 is the difference of 2 positive pentagonal numbers in 2 ways.
661057 = 2642 + 7692 = 1212 + 8042 is the sum of 2 positive squares in 2 ways.
661057 = 142 + 692 + 8102 is the sum of 3 positive squares.
6610572 = 1945682 + 6317752 = 1192072 + 6502202 = 4060322 + 5216652 = 3053052 + 5863322 is the sum of 2 positive squares in 4 ways.
6610572 is the sum of 3 positive squares.
661057 is a proper divisor of 367252 - 1.
661057 is an emirpimes in (at least) the following bases: 7, 10, 11, 12, 17, 19, 25, 26, 28, 29, 31, 33, 37, 44, 45, 48, 50, 53, 55, 59, 64, 67, 69, 70, 74, 76, 78, 79, 80, 83, 85, 88, 91, 92, 93, 95, and 100.
661057 is palindromic in (at least) base -18.
661057 in base 60 = 33bb and consists of only the digits '3' and 'b'.