664495668 has 36 divisors (see below), whose sum is σ = 1752729888. Its totient is φ = 211867920.

The previous prime is 664495661. The next prime is 664495669. The reversal of 664495668 is 866594466.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664495661) 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, 400438 + ... + 402093.

Almost surely, 2^664495668 is an apocalyptic number.

It is an amenable number.

664495668 is an abundant number, since it is smaller than the sum of its proper divisors (1088234220).

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

664495668 is a wasteful number, since it uses less digits than its factorization.

664495668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802564 (or 802559 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 54.

The square root of 664495668 is about 25777.8134836917. The cubic root of 664495668 is about 872.6311625104.

The spelling of 664495668 in words is "six hundred sixty-four million, four hundred ninety-five thousand, six hundred sixty-eight".