399424740 has 144 divisors (see below), whose sum is σ = 1321500096. Its totient is φ = 89356800.

The previous prime is 399424709. The next prime is 399424763. The reversal of 399424740 is 47424993.

It is a junction number, because it is equal to n+sod(n) for n = 399424692 and 399424701.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 109750 + ... + 113330.

It is an arithmetic number, because the mean of its divisors is an integer number (9177084).

Almost surely, 2^399424740 is an apocalyptic number.

399424740 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399424740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (660750048).

399424740 is an abundant number, since it is smaller than the sum of its proper divisors (922075356).

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

399424740 is a wasteful number, since it uses less digits than its factorization.

399424740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3630 (or 3615 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 42.

The square root of 399424740 is about 19985.6133255900. The cubic root of 399424740 is about 736.4529176084.

The spelling of 399424740 in words is "three hundred ninety-nine million, four hundred twenty-four thousand, seven hundred forty".