664464901 has 4 divisors (see below), whose sum is σ = 680671404. Its totient is φ = 648258400.

The previous prime is 664464863. The next prime is 664464919. The reversal of 664464901 is 109464466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69056100 + 595408801 = 8310^2 + 24401^2 .

It is a cyclic number.

It is not a de Polignac number, because 664464901 - 2²¹ = 662367749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664464001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8103190 + ... + 8103271.

It is an arithmetic number, because the mean of its divisors is an integer number (170167851).

Almost surely, 2^664464901 is an apocalyptic number.

It is an amenable number.

664464901 is a deficient number, since it is larger than the sum of its proper divisors (16206503).

664464901 is a wasteful number, since it uses less digits than its factorization.

664464901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16206502.

The product of its (nonzero) digits is 124416, while the sum is 40.

The square root of 664464901 is about 25777.2167039035. The cubic root of 664464901 is about 872.6176943225.

The spelling of 664464901 in words is "six hundred sixty-four million, four hundred sixty-four thousand, nine hundred one".