390390820 has 12 divisors (see below), whose sum is σ = 819820764. Its totient is φ = 156156320.

The previous prime is 390390817. The next prime is 390390827. The reversal of 390390820 is 28093093.

It can be written as a sum of positive squares in 2 ways, for example, as 161594944 + 228795876 = 12712^2 + 15126^2 .

It is not an unprimeable number, because it can be changed into a prime (390390827) 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, 9759751 + ... + 9759790.

It is an arithmetic number, because the mean of its divisors is an integer number (68318397).

Almost surely, 2^390390820 is an apocalyptic number.

It is an amenable number.

390390820 is an abundant number, since it is smaller than the sum of its proper divisors (429429944).

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

390390820 is a wasteful number, since it uses less digits than its factorization.

390390820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19519550 (or 19519548 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 390390820 is about 19758.3101504152. The cubic root of 390390820 is about 730.8583261042.

The spelling of 390390820 in words is "three hundred ninety million, three hundred ninety thousand, eight hundred twenty".