390979621 has 8 divisors (see below), whose sum is σ = 395623800. Its totient is φ = 386354880.

The previous prime is 390979613. The next prime is 390979627. The reversal of 390979621 is 126979093.

It can be written as a sum of positive squares in 4 ways, for example, as 125126596 + 265853025 = 11186^2 + 16305^2 .

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 390979621 - 2³ = 390979613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390979627) 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, 37791 + ... + 47011.

It is an arithmetic number, because the mean of its divisors is an integer number (49452975).

Almost surely, 2^390979621 is an apocalyptic number.

It is an amenable number.

390979621 is a deficient number, since it is larger than the sum of its proper divisors (4644179).

390979621 is a wasteful number, since it uses less digits than its factorization.

390979621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9719.

The product of its (nonzero) digits is 183708, while the sum is 46.

The square root of 390979621 is about 19773.2046214062. The cubic root of 390979621 is about 731.2255768403.

The spelling of 390979621 in words is "three hundred ninety million, nine hundred seventy-nine thousand, six hundred twenty-one".