57204121561 has 2 divisors, whose sum is σ = 57204121562. Its totient is φ = 57204121560.

The previous prime is 57204121549. The next prime is 57204121567. The reversal of 57204121561 is 16512140275.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35261328400 + 21942793161 = 187780^2 + 148131^2 .

It is a cyclic number.

It is not a de Polignac number, because 57204121561 - 2⁵ = 57204121529 is a prime.

It is not a weakly prime, because it can be changed into another prime (57204121567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28602060780 + 28602060781.

It is an arithmetic number, because the mean of its divisors is an integer number (28602060781).

Almost surely, 2^57204121561 is an apocalyptic number.

It is an amenable number.

57204121561 is a deficient number, since it is larger than the sum of its proper divisors (1).

57204121561 is an equidigital number, since it uses as much as digits as its factorization.

57204121561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16800, while the sum is 34.

The spelling of 57204121561 in words is "fifty-seven billion, two hundred four million, one hundred twenty-one thousand, five hundred sixty-one".