390531920 has 20 divisors (see below), whose sum is σ = 907986900. Its totient is φ = 156212736.

The previous prime is 390531913. The next prime is 390531923. The reversal of 390531920 is 29135093.

It can be written as a sum of positive squares in 2 ways, for example, as 70694464 + 319837456 = 8408^2 + 17884^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390531923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2440745 + ... + 2440904.

It is an arithmetic number, because the mean of its divisors is an integer number (45399345).

Almost surely, 2^390531920 is an apocalyptic number.

It is an amenable number.

390531920 is an abundant number, since it is smaller than the sum of its proper divisors (517454980).

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

390531920 is a wasteful number, since it uses less digits than its factorization.

390531920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4881662 (or 4881656 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 390531920 is about 19761.8804773230. The cubic root of 390531920 is about 730.9463675256.

The spelling of 390531920 in words is "three hundred ninety million, five hundred thirty-one thousand, nine hundred twenty".