664155400 has 24 divisors (see below), whose sum is σ = 1544161770. Its totient is φ = 265662080.

The previous prime is 664155397. The next prime is 664155403. The reversal of 664155400 is 4551466.

It is an interprime number because it is at equal distance from previous prime (664155397) and next prime (664155403).

It can be written as a sum of positive squares in 3 ways, for example, as 245298244 + 418857156 = 15662^2 + 20466^2 .

It is a super-2 number, since 2×664155400² = 882204790698320000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664155403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1660189 + ... + 1660588.

Almost surely, 2^664155400 is an apocalyptic number.

It is an amenable number.

664155400 is an abundant number, since it is smaller than the sum of its proper divisors (880006370).

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

664155400 is a wasteful number, since it uses less digits than its factorization.

664155400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3320793 (or 3320784 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 664155400 is about 25771.2126218383. The cubic root of 664155400 is about 872.4821877957.

The spelling of 664155400 in words is "six hundred sixty-four million, one hundred fifty-five thousand, four hundred".