399591936 has 120 divisors (see below), whose sum is σ = 1221326964. Its totient is φ = 125337600.

The previous prime is 399591931. The next prime is 399591961. The reversal of 399591936 is 639195993.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 377913600 + 21678336 = 19440^2 + 4656^2 .

It is not an unprimeable number, because it can be changed into a prime (399591931) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 75786 + ... + 80886.

Almost surely, 2^399591936 is an apocalyptic number.

399591936 is a gapful number since it is divisible by the number (36) 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 399591936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (610663482).

399591936 is an abundant number, since it is smaller than the sum of its proper divisors (821735028).

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

399591936 is a wasteful number, since it uses less digits than its factorization.

399591936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5142 (or 5123 counting only the distinct ones).

The product of its digits is 1771470, while the sum is 54.

The square root of 399591936 is about 19989.7957968560. The cubic root of 399591936 is about 736.5556610400. Note that the first 3 decimals are identical.

The spelling of 399591936 in words is "three hundred ninety-nine million, five hundred ninety-one thousand, nine hundred thirty-six".