399784020 has 24 divisors (see below), whose sum is σ = 1119395424. Its totient is φ = 106609056.

The previous prime is 399784013. The next prime is 399784061. The reversal of 399784020 is 20487993.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3331474 + ... + 3331593.

It is an arithmetic number, because the mean of its divisors is an integer number (46641476).

Almost surely, 2^399784020 is an apocalyptic number.

399784020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399784020 is an abundant number, since it is smaller than the sum of its proper divisors (719611404).

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

399784020 is a wasteful number, since it uses less digits than its factorization.

399784020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6663079 (or 6663077 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 399784020 is about 19994.5997709382. The cubic root of 399784020 is about 736.6736629990.

The spelling of 399784020 in words is "three hundred ninety-nine million, seven hundred eighty-four thousand, twenty".