400025664 has 168 divisors, whose sum is σ = 1188720000. Its totient is φ = 128553984.

The previous prime is 400025663. The next prime is 400025693. The reversal of 400025664 is 466520004.

It is a happy number.

400025664 is a `hidden beast` number, since 400 + 0 + 256 + 6 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (400025663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2684662 + ... + 2684810.

Almost surely, 2^400025664 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 400025664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (594360000).

400025664 is an abundant number, since it is smaller than the sum of its proper divisors (788694336).

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

400025664 is a wasteful number, since it uses less digits than its factorization.

400025664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 400025664 is about 20000.6415897091. The cubic root of 400025664 is about 736.8220572218.

Adding to 400025664 its reverse (466520004), we get a palindrome (866545668).

It can be divided in two parts, 400025 and 664, that added together give a square (400689 = 633²).

The spelling of 400025664 in words is "four hundred million, twenty-five thousand, six hundred sixty-four".