391689436 has 24 divisors (see below), whose sum is σ = 699229440. Its totient is φ = 191930352.

The previous prime is 391689421. The next prime is 391689449. The reversal of 391689436 is 634986193.

It is a super-2 number, since 2×391689436² = 306841228547996192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 391689436.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79501 + ... + 84283.

It is an arithmetic number, because the mean of its divisors is an integer number (29134560).

Almost surely, 2^391689436 is an apocalyptic number.

It is an amenable number.

391689436 is a deficient number, since it is larger than the sum of its proper divisors (307540004).

391689436 is a wasteful number, since it uses less digits than its factorization.

391689436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5193 (or 5191 counting only the distinct ones).

The product of its digits is 839808, while the sum is 49.

The square root of 391689436 is about 19791.1453938371. The cubic root of 391689436 is about 731.6678173669.

The spelling of 391689436 in words is "three hundred ninety-one million, six hundred eighty-nine thousand, four hundred thirty-six".