56720557 has 2 divisors, whose sum is σ = 56720558. Its totient is φ = 56720556.

The previous prime is 56720537. The next prime is 56720591. The reversal of 56720557 is 75502765.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47073321 + 9647236 = 6861^2 + 3106^2 .

It is a cyclic number.

It is not a de Polignac number, because 56720557 - 2¹⁹ = 56196269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56720537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28360278 + 28360279.

It is an arithmetic number, because the mean of its divisors is an integer number (28360279).

Almost surely, 2^56720557 is an apocalyptic number.

It is an amenable number.

56720557 is a deficient number, since it is larger than the sum of its proper divisors (1).

56720557 is an equidigital number, since it uses as much as digits as its factorization.

56720557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 73500, while the sum is 37.

The square root of 56720557 is about 7531.3051325783. The cubic root of 56720557 is about 384.2201722213.

The spelling of 56720557 in words is "fifty-six million, seven hundred twenty thousand, five hundred fifty-seven".