391204979 has 12 divisors (see below), whose sum is σ = 435194088. Its totient is φ = 351347040.

The previous prime is 391204973. The next prime is 391204993. The reversal of 391204979 is 979402193.

It is not a de Polignac number, because 391204979 - 2¹² = 391200883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391204973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9434 + ... + 29519.

It is an arithmetic number, because the mean of its divisors is an integer number (36266174).

Almost surely, 2^391204979 is an apocalyptic number.

391204979 is a deficient number, since it is larger than the sum of its proper divisors (43989109).

391204979 is a wasteful number, since it uses less digits than its factorization.

391204979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39058 (or 39047 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 391204979 is about 19778.9023709608. The cubic root of 391204979 is about 731.3660410095.

The spelling of 391204979 in words is "three hundred ninety-one million, two hundred four thousand, nine hundred seventy-nine".