399953640 has 64 divisors (see below), whose sum is σ = 1201210560. Its totient is φ = 106534400.

The previous prime is 399953639. The next prime is 399953657. The reversal of 399953640 is 46359993.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 399953640.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 172972 + ... + 175268.

It is an arithmetic number, because the mean of its divisors is an integer number (18768915).

Almost surely, 2^399953640 is an apocalyptic number.

399953640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399953640 is an abundant number, since it is smaller than the sum of its proper divisors (801256920).

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

399953640 is a wasteful number, since it uses less digits than its factorization.

399953640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3762 (or 3758 counting only the distinct ones).

The product of its (nonzero) digits is 787320, while the sum is 48.

The square root of 399953640 is about 19998.8409664160. The cubic root of 399953640 is about 736.7778333449. Note that the first 3 decimals are identical.

The spelling of 399953640 in words is "three hundred ninety-nine million, nine hundred fifty-three thousand, six hundred forty".