56661569 has 2 divisors, whose sum is σ = 56661570. Its totient is φ = 56661568.

The previous prime is 56661559. The next prime is 56661587. The reversal of 56661569 is 96516665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39753025 + 16908544 = 6305^2 + 4112^2 .

It is a cyclic number.

It is not a de Polignac number, because 56661569 - 2¹² = 56657473 is a prime.

It is a super-2 number, since 2×56661569² = 6421066803083522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (56661559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28330784 + 28330785.

It is an arithmetic number, because the mean of its divisors is an integer number (28330785).

Almost surely, 2^56661569 is an apocalyptic number.

It is an amenable number.

56661569 is a deficient number, since it is larger than the sum of its proper divisors (1).

56661569 is an equidigital number, since it uses as much as digits as its factorization.

56661569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 291600, while the sum is 44.

The square root of 56661569 is about 7527.3879267645. The cubic root of 56661569 is about 384.0869328101.

The spelling of 56661569 in words is "fifty-six million, six hundred sixty-one thousand, five hundred sixty-nine".