391996969 has 16 divisors (see below), whose sum is σ = 483864192. Its totient is φ = 309247488.

The previous prime is 391996951. The next prime is 391997009. The reversal of 391996969 is 969699193.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 391996969 - 2⁵ = 391996937 is a prime.

It is a super-2 number, since 2×391996969² = 307323247410373922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (391996909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26022 + ... + 38224.

It is an arithmetic number, because the mean of its divisors is an integer number (30241512).

Almost surely, 2^391996969 is an apocalyptic number.

It is an amenable number.

391996969 is a deficient number, since it is larger than the sum of its proper divisors (91867223).

391996969 is a wasteful number, since it uses less digits than its factorization.

391996969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12576.

The product of its digits is 6377292, while the sum is 61.

The square root of 391996969 is about 19798.9133287663. The cubic root of 391996969 is about 731.8592557148.

The spelling of 391996969 in words is "three hundred ninety-one million, nine hundred ninety-six thousand, nine hundred sixty-nine".