664005400 has 48 divisors (see below), whose sum is σ = 1610946000. Its totient is φ = 254052480.

The previous prime is 664005389. The next prime is 664005409. The reversal of 664005400 is 4500466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664005409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67575 + ... + 76774.

It is an arithmetic number, because the mean of its divisors is an integer number (33561375).

Almost surely, 2^664005400 is an apocalyptic number.

It is an amenable number.

664005400 is an abundant number, since it is smaller than the sum of its proper divisors (946940600).

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

664005400 is a wasteful number, since it uses less digits than its factorization.

664005400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144388 (or 144379 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 664005400 is about 25768.3022335582. The cubic root of 664005400 is about 872.4164992626.

Adding to 664005400 its reverse (4500466), we get a palindrome (668505866).

The spelling of 664005400 in words is "six hundred sixty-four million, five thousand, four hundred".