399942660 has 48 divisors (see below), whose sum is σ = 1205983296. Its totient is φ = 98447232.

The previous prime is 399942649. The next prime is 399942661. The reversal of 399942660 is 66249993.

It is not an unprimeable number, because it can be changed into a prime (399942661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255594 + ... + 257153.

It is an arithmetic number, because the mean of its divisors is an integer number (25124652).

Almost surely, 2^399942660 is an apocalyptic number.

399942660 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399942660 is an abundant number, since it is smaller than the sum of its proper divisors (806040636).

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

399942660 is a wasteful number, since it uses less digits than its factorization.

399942660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512772 (or 512770 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 48.

The square root of 399942660 is about 19998.5664486233. The cubic root of 399942660 is about 736.7710909846.

The spelling of 399942660 in words is "three hundred ninety-nine million, nine hundred forty-two thousand, six hundred sixty".