391320651 has 4 divisors (see below), whose sum is σ = 521760872. Its totient is φ = 260880432.

The previous prime is 391320613. The next prime is 391320653. The reversal of 391320651 is 156023193.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 391320651 - 2²² = 387126347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391320653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65220106 + ... + 65220111.

It is an arithmetic number, because the mean of its divisors is an integer number (130440218).

Almost surely, 2^391320651 is an apocalyptic number.

391320651 is a deficient number, since it is larger than the sum of its proper divisors (130440221).

391320651 is a wasteful number, since it uses less digits than its factorization.

391320651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130440220.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 391320651 is about 19781.8262807052. The cubic root of 391320651 is about 731.4381176620.

The spelling of 391320651 in words is "three hundred ninety-one million, three hundred twenty thousand, six hundred fifty-one".