399638442 has 16 divisors (see below), whose sum is σ = 913459392. Its totient is φ = 114182400.

The previous prime is 399638423. The next prime is 399638467. The reversal of 399638442 is 244836993.

It is a junction number, because it is equal to n+sod(n) for n = 399638391 and 399638400.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4757559 + ... + 4757642.

It is an arithmetic number, because the mean of its divisors is an integer number (57091212).

Almost surely, 2^399638442 is an apocalyptic number.

399638442 is an abundant number, since it is smaller than the sum of its proper divisors (513820950).

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

399638442 is a wasteful number, since it uses less digits than its factorization.

399638442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9515213.

The product of its digits is 1119744, while the sum is 48.

The square root of 399638442 is about 19990.9590065109. The cubic root of 399638442 is about 736.5842342966.

The spelling of 399638442 in words is "three hundred ninety-nine million, six hundred thirty-eight thousand, four hundred forty-two".