390915220 has 12 divisors (see below), whose sum is σ = 820922004. Its totient is φ = 156366080.

The previous prime is 390915169. The next prime is 390915223. The reversal of 390915220 is 22519093.

It can be written as a sum of positive squares in 2 ways, for example, as 280160644 + 110754576 = 16738^2 + 10524^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390915223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9772861 + ... + 9772900.

It is an arithmetic number, because the mean of its divisors is an integer number (68410167).

Almost surely, 2^390915220 is an apocalyptic number.

It is an amenable number.

390915220 is an abundant number, since it is smaller than the sum of its proper divisors (430006784).

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

390915220 is a wasteful number, since it uses less digits than its factorization.

390915220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19545770 (or 19545768 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 390915220 is about 19771.5760626208. The cubic root of 390915220 is about 731.1854262019.

The spelling of 390915220 in words is "three hundred ninety million, nine hundred fifteen thousand, two hundred twenty".