399429738 has 16 divisors (see below), whose sum is σ = 887621760. Its totient is φ = 133143228.

The previous prime is 399429733. The next prime is 399429743. The reversal of 399429738 is 837924993.

It is an interprime number because it is at equal distance from previous prime (399429733) and next prime (399429743).

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 7396847 = 399429738 / (3 + 9 + 9 + 4 + 2 + 9 + 7 + 3 + 8).

It is not an unprimeable number, because it can be changed into a prime (399429733) 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, 3698370 + ... + 3698477.

It is an arithmetic number, because the mean of its divisors is an integer number (55476360).

Almost surely, 2^399429738 is an apocalyptic number.

399429738 is an abundant number, since it is smaller than the sum of its proper divisors (488192022).

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

399429738 is a wasteful number, since it uses less digits than its factorization.

399429738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7396858 (or 7396852 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 54.

The square root of 399429738 is about 19985.7383651443. The cubic root of 399429738 is about 736.4559893396.

The spelling of 399429738 in words is "three hundred ninety-nine million, four hundred twenty-nine thousand, seven hundred thirty-eight".