391616517 has 4 divisors (see below), whose sum is σ = 522155360. Its totient is φ = 261077676.

The previous prime is 391616501. The next prime is 391616527. The reversal of 391616517 is 715616193.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 391616517 - 2⁴ = 391616501 is a prime.

It is a super-2 number, since 2×391616517² = 306726992774422578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391616527) 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, 65269417 + ... + 65269422.

It is an arithmetic number, because the mean of its divisors is an integer number (130538840).

Almost surely, 2^391616517 is an apocalyptic number.

It is an amenable number.

391616517 is a deficient number, since it is larger than the sum of its proper divisors (130538843).

391616517 is a wasteful number, since it uses less digits than its factorization.

391616517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130538842.

The product of its digits is 34020, while the sum is 39.

The square root of 391616517 is about 19789.3030953594. The cubic root of 391616517 is about 731.6224108179.

The spelling of 391616517 in words is "three hundred ninety-one million, six hundred sixteen thousand, five hundred seventeen".