57944806921 has 2 divisors, whose sum is σ = 57944806922. Its totient is φ = 57944806920.

The previous prime is 57944806891. The next prime is 57944806943. The reversal of 57944806921 is 12960844975.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38565104400 + 19379702521 = 196380^2 + 139211^2 .

It is a cyclic number.

It is not a de Polignac number, because 57944806921 - 2¹⁷ = 57944675849 is a prime.

It is a super-2 number, since 2×57944806921² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (57944806981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28972403460 + 28972403461.

It is an arithmetic number, because the mean of its divisors is an integer number (28972403461).

Almost surely, 2^57944806921 is an apocalyptic number.

It is an amenable number.

57944806921 is a deficient number, since it is larger than the sum of its proper divisors (1).

57944806921 is an equidigital number, since it uses as much as digits as its factorization.

57944806921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 57944806921 in words is "fifty-seven billion, nine hundred forty-four million, eight hundred six thousand, nine hundred twenty-one".