399474540 has 72 divisors (see below), whose sum is σ = 1215854640. Its totient is φ = 106164864.

The previous prime is 399474527. The next prime is 399474571. The reversal of 399474540 is 45474993.

It is a happy number.

399474540 is a `hidden beast` number, since 39 + 9 + 4 + 74 + 540 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51646 + ... + 58874.

It is an arithmetic number, because the mean of its divisors is an integer number (16886870).

Almost surely, 2^399474540 is an apocalyptic number.

399474540 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 399474540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (607927320).

399474540 is an abundant number, since it is smaller than the sum of its proper divisors (816380100).

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

399474540 is a wasteful number, since it uses less digits than its factorization.

399474540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7551 (or 7546 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 399474540 is about 19986.8591829732. The cubic root of 399474540 is about 736.4835231498.

The spelling of 399474540 in words is "three hundred ninety-nine million, four hundred seventy-four thousand, five hundred forty".