391131313 has 8 divisors (see below), whose sum is σ = 393869480. Its totient is φ = 388402560.

The previous prime is 391131281. The next prime is 391131317. The reversal of 391131313 is 313131193.

It can be written as a sum of positive squares in 4 ways, for example, as 34374769 + 356756544 = 5863^2 + 18888^2 .

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 391131313 - 2⁵ = 391131281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391131317) 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, 94381 + ... + 98437.

It is an arithmetic number, because the mean of its divisors is an integer number (49233685).

Almost surely, 2^391131313 is an apocalyptic number.

It is an amenable number.

391131313 is a deficient number, since it is larger than the sum of its proper divisors (2738167).

391131313 is a wasteful number, since it uses less digits than its factorization.

391131313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4707.

The product of its digits is 729, while the sum is 25.

The square root of 391131313 is about 19777.0400464781. The cubic root of 391131313 is about 731.3201314090.

The spelling of 391131313 in words is "three hundred ninety-one million, one hundred thirty-one thousand, three hundred thirteen".