7991957 has 2 divisors, whose sum is σ = 7991958. Its totient is φ = 7991956.

The previous prime is 7991953. The next prime is 7991981. The reversal of 7991957 is 7591997.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5958481 + 2033476 = 2441^2 + 1426^2 .

It is a cyclic number.

It is not a de Polignac number, because 7991957 - 2² = 7991953 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7991953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3995978 + 3995979.

It is an arithmetic number, because the mean of its divisors is an integer number (3995979).

Almost surely, 2^7991957 is an apocalyptic number.

It is an amenable number.

7991957 is a deficient number, since it is larger than the sum of its proper divisors (1).

7991957 is an equidigital number, since it uses as much as digits as its factorization.

7991957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 178605, while the sum is 47.

The square root of 7991957 is about 2827.0049522419. The cubic root of 7991957 is about 199.9329525257.

The spelling of 7991957 in words is "seven million, nine hundred ninety-one thousand, nine hundred fifty-seven".