57991891 has 2 divisors, whose sum is σ = 57991892. Its totient is φ = 57991890.

The previous prime is 57991823. The next prime is 57991931. The reversal of 57991891 is 19819975.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 57991891 - 2²¹ = 55894739 is a prime.

It is not a weakly prime, because it can be changed into another prime (57991991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28995945 + 28995946.

It is an arithmetic number, because the mean of its divisors is an integer number (28995946).

Almost surely, 2^57991891 is an apocalyptic number.

57991891 is a deficient number, since it is larger than the sum of its proper divisors (1).

57991891 is an equidigital number, since it uses as much as digits as its factorization.

57991891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 49.

The square root of 57991891 is about 7615.2407053225. The cubic root of 57991891 is about 387.0696236021.

The spelling of 57991891 in words is "fifty-seven million, nine hundred ninety-one thousand, eight hundred ninety-one".