399131712 has 280 divisors, whose sum is σ = 1433925504. Its totient is φ = 107163648.

The previous prime is 399131701. The next prime is 399131749. The reversal of 399131712 is 217131993.

It is a happy number.

It is a super-2 number, since 2×399131712² = 318612247048101888, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 616573 + ... + 617219.

Almost surely, 2^399131712 is an apocalyptic number.

399131712 is a gapful number since it is divisible by the number (32) 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 399131712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (716962752).

399131712 is an abundant number, since it is smaller than the sum of its proper divisors (1034793792).

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

399131712 is a wasteful number, since it uses less digits than its factorization.

399131712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695 (or 676 counting only the distinct ones).

The product of its digits is 10206, while the sum is 36.

The square root of 399131712 is about 19978.2810071337. The cubic root of 399131712 is about 736.2727801108.

The spelling of 399131712 in words is "three hundred ninety-nine million, one hundred thirty-one thousand, seven hundred twelve".