399524736 has 128 divisors (see below), whose sum is σ = 1152224640. Its totient is φ = 121927680.

The previous prime is 399524729. The next prime is 399524737. The reversal of 399524736 is 637425993.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399524737) 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 15 ways as a sum of consecutive naturals, for example, 813451 + ... + 813941.

It is an arithmetic number, because the mean of its divisors is an integer number (9001755).

Almost surely, 2^399524736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399524736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (576112320).

399524736 is an abundant number, since it is smaller than the sum of its proper divisors (752699904).

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

399524736 is a wasteful number, since it uses less digits than its factorization.

399524736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684 (or 672 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 48.

The square root of 399524736 is about 19988.1148685913. The cubic root of 399524736 is about 736.5143694866.

The spelling of 399524736 in words is "three hundred ninety-nine million, five hundred twenty-four thousand, seven hundred thirty-six".