399818520 has 96 divisors (see below), whose sum is σ = 1367823600. Its totient is φ = 101005056.

The previous prime is 399818513. The next prime is 399818543. The reversal of 399818520 is 25818993.

It is a happy number.

399818520 is a `hidden beast` number, since 39 + 98 + 1 + 8 + 520 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22387 + ... + 36066.

Almost surely, 2^399818520 is an apocalyptic number.

399818520 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399818520 is an abundant number, since it is smaller than the sum of its proper divisors (968005080).

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

399818520 is a wasteful number, since it uses less digits than its factorization.

399818520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58489 (or 58482 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 399818520 is about 19995.4624852740. The cubic root of 399818520 is about 736.6948531992.

The spelling of 399818520 in words is "three hundred ninety-nine million, eight hundred eighteen thousand, five hundred twenty".