399349440 has 560 divisors, whose sum is σ = 1699467264. Its totient is φ = 87091200.

The previous prime is 399349427. The next prime is 399349441. The reversal of 399349440 is 44943993.

399349440 is a `hidden beast` number, since 39 + 93 + 494 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (399349441) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5624605 + ... + 5624675.

Almost surely, 2^399349440 is an apocalyptic number.

399349440 is a gapful number since it is divisible by the number (30) 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 399349440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (849733632).

399349440 is an abundant number, since it is smaller than the sum of its proper divisors (1300117824).

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

399349440 is a wasteful number, since it uses less digits than its factorization.

399349440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 45.

The square root of 399349440 is about 19983.7293816745. The cubic root of 399349440 is about 736.4066357232.

The spelling of 399349440 in words is "three hundred ninety-nine million, three hundred forty-nine thousand, four hundred forty".