7957665991 has 8 divisors (see below), whose sum is σ = 8687840400. Its totient is φ = 7228616640.

The previous prime is 7957665959. The next prime is 7957666007. The reversal of 7957665991 is 1995667597.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 7957665991 - 2⁵ = 7957665959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7957665901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 266436 + ... + 294793.

It is an arithmetic number, because the mean of its divisors is an integer number (1085980050).

Almost surely, 2^7957665991 is an apocalyptic number.

7957665991 is a deficient number, since it is larger than the sum of its proper divisors (730174409).

7957665991 is a wasteful number, since it uses less digits than its factorization.

7957665991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562529.

The product of its digits is 32148900, while the sum is 64.

The square root of 7957665991 is about 89205.7508852428. The cubic root of 7957665991 is about 1996.4659247510.

The spelling of 7957665991 in words is "seven billion, nine hundred fifty-seven million, six hundred sixty-five thousand, nine hundred ninety-one".