390821380 has 24 divisors (see below), whose sum is σ = 842908248. Its totient is φ = 152103168.

The previous prime is 390821363. The next prime is 390821383. The reversal of 390821380 is 83128093.

It can be written as a sum of positive squares in 4 ways, for example, as 64224196 + 326597184 = 8014^2 + 18072^2 .

It is not an unprimeable number, because it can be changed into a prime (390821383) 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, 263329 + ... + 264808.

It is an arithmetic number, because the mean of its divisors is an integer number (35121177).

Almost surely, 2^390821380 is an apocalyptic number.

It is an amenable number.

390821380 is an abundant number, since it is smaller than the sum of its proper divisors (452086868).

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

390821380 is a wasteful number, since it uses less digits than its factorization.

390821380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528183 (or 528181 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 390821380 is about 19769.2028165022. The cubic root of 390821380 is about 731.1269139994.

The spelling of 390821380 in words is "three hundred ninety million, eight hundred twenty-one thousand, three hundred eighty".