664728477 has 32 divisors (see below), whose sum is σ = 1023202560. Its totient is φ = 376012800.

The previous prime is 664728469. The next prime is 664728481. The reversal of 664728477 is 774827466.

It is a happy number.

It is not a de Polignac number, because 664728477 - 2³ = 664728469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664728457) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1625049 + ... + 1625457.

It is an arithmetic number, because the mean of its divisors is an integer number (31975080).

Almost surely, 2^664728477 is an apocalyptic number.

It is an amenable number.

664728477 is a deficient number, since it is larger than the sum of its proper divisors (358474083).

664728477 is a wasteful number, since it uses less digits than its factorization.

664728477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013.

The product of its digits is 3161088, while the sum is 51.

The square root of 664728477 is about 25782.3287737939. The cubic root of 664728477 is about 872.7330606752.

The spelling of 664728477 in words is "six hundred sixty-four million, seven hundred twenty-eight thousand, four hundred seventy-seven".