957991 has 2 divisors, whose sum is σ = 957992. Its totient is φ = 957990.

The previous prime is 957977. The next prime is 958007. The reversal of 957991 is 199759.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 957991 - 2⁵ = 957959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (957091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 478995 + 478996.

It is an arithmetic number, because the mean of its divisors is an integer number (478996).

2⁹⁵⁷⁹⁹¹ is an apocalyptic number.

957991 is a deficient number, since it is larger than the sum of its proper divisors (1).

957991 is an equidigital number, since it uses as much as digits as its factorization.

957991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25515, while the sum is 40.

The square root of 957991 is about 978.7701466637. The cubic root of 957991 is about 98.5796207472.

The spelling of 957991 in words is "nine hundred fifty-seven thousand, nine hundred ninety-one".