391664252 has 36 divisors (see below), whose sum is σ = 839288520. Its totient is φ = 159020064.

The previous prime is 391664249. The next prime is 391664281. The reversal of 391664252 is 252466193.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48863 + ... + 56310.

It is an arithmetic number, because the mean of its divisors is an integer number (23313570).

Almost surely, 2^391664252 is an apocalyptic number.

It is an amenable number.

391664252 is an abundant number, since it is smaller than the sum of its proper divisors (447624268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391664252 is a wasteful number, since it uses less digits than its factorization.

391664252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105210 (or 105201 counting only the distinct ones).

The product of its digits is 77760, while the sum is 38.

The square root of 391664252 is about 19790.5091394840. The cubic root of 391664252 is about 731.6521359660.

The spelling of 391664252 in words is "three hundred ninety-one million, six hundred sixty-four thousand, two hundred fifty-two".