399424240 has 40 divisors (see below), whose sum is σ = 935774928. Its totient is φ = 158545920.

The previous prime is 399424229. The next prime is 399424247. The reversal of 399424240 is 42424993.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 399424240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399424247) 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, 8577 + ... + 29536.

Almost surely, 2^399424240 is an apocalyptic number.

It is an amenable number.

399424240 is an abundant number, since it is smaller than the sum of its proper divisors (536350688).

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

399424240 is a wasteful number, since it uses less digits than its factorization.

399424240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38257 (or 38251 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

The square root of 399424240 is about 19985.6008165879. The cubic root of 399424240 is about 736.4526103110.

The spelling of 399424240 in words is "three hundred ninety-nine million, four hundred twenty-four thousand, two hundred forty".