400120668864 has 840 divisors, whose sum is σ = 1430929307808. Its totient is φ = 110152949760.

The previous prime is 400120668799. The next prime is 400120668889. The reversal of 400120668864 is 468866021004.

400120668864 is a `hidden beast` number, since 400 + 120 + 6 + 68 + 8 + 64 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1072709382 + ... + 1072709754.

Almost surely, 2^400120668864 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 400120668864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (715464653904).

400120668864 is an abundant number, since it is smaller than the sum of its proper divisors (1030808638944).

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

400120668864 is a wasteful number, since it uses less digits than its factorization.

400120668864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 529 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

Adding to 400120668864 its reverse (468866021004), we get a palindrome (868986689868).

The spelling of 400120668864 in words is "four hundred billion, one hundred twenty million, six hundred sixty-eight thousand, eight hundred sixty-four".