399603456 has 180 divisors, whose sum is σ = 1362260592. Its totient is φ = 114130944.

The previous prime is 399603443. The next prime is 399603461. The reversal of 399603456 is 654306993.

It is a happy number.

399603456 is a `hidden beast` number, since 39 + 9 + 603 + 4 + 5 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 143776 + ... + 146528.

Almost surely, 2^399603456 is an apocalyptic number.

399603456 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 399603456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (681130296).

399603456 is an abundant number, since it is smaller than the sum of its proper divisors (962657136).

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

399603456 is an equidigital number, since it uses as much as digits as its factorization.

399603456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2788 (or 2765 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 45.

The square root of 399603456 is about 19990.0839417947. The cubic root of 399603456 is about 736.5627391272.

The spelling of 399603456 in words is "three hundred ninety-nine million, six hundred three thousand, four hundred fifty-six".