7965991 has 8 divisors (see below), whose sum is σ = 8740368. Its totient is φ = 7200000.

The previous prime is 7965949. The next prime is 7966001. The reversal of 7965991 is 1995697.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 8-Lehmer number, since φ(7965991) divides (7965991-1)⁸.

It is a cyclic number.

It is not a de Polignac number, because 7965991 - 2⁷ = 7965863 is a prime.

It is a super-2 number, since 2×7965991² = 126914025224162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7965941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10 + ... + 3991.

It is an arithmetic number, because the mean of its divisors is an integer number (1092546).

Almost surely, 2^7965991 is an apocalyptic number.

7965991 is a deficient number, since it is larger than the sum of its proper divisors (774377).

7965991 is a wasteful number, since it uses less digits than its factorization.

7965991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4193.

The product of its digits is 153090, while the sum is 46.

The square root of 7965991 is about 2822.4087230591. The cubic root of 7965991 is about 199.7161891141.

The spelling of 7965991 in words is "seven million, nine hundred sixty-five thousand, nine hundred ninety-one".