391475257 has 8 divisors (see below), whose sum is σ = 406103040. Its totient is φ = 377089440.

The previous prime is 391475251. The next prime is 391475317. The reversal of 391475257 is 752574193.

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 391475257 - 2²⁷ = 257257529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391475251) 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, 57193 + ... + 63670.

It is an arithmetic number, because the mean of its divisors is an integer number (50762880).

Almost surely, 2^391475257 is an apocalyptic number.

It is an amenable number.

391475257 is a deficient number, since it is larger than the sum of its proper divisors (14627783).

391475257 is a wasteful number, since it uses less digits than its factorization.

391475257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120983.

The product of its digits is 264600, while the sum is 43.

The square root of 391475257 is about 19785.7336735336. The cubic root of 391475257 is about 731.5344323950.

The spelling of 391475257 in words is "three hundred ninety-one million, four hundred seventy-five thousand, two hundred fifty-seven".