64400664 has 16 divisors (see below), whose sum is σ = 161001720. Its totient is φ = 21466880.

The previous prime is 64400663. The next prime is 64400717. The reversal of 64400664 is 46600446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64400663) 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, 1341657 + ... + 1341704.

Almost surely, 2^64400664 is an apocalyptic number.

It is an amenable number.

64400664 is an abundant number, since it is smaller than the sum of its proper divisors (96601056).

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

64400664 is a wasteful number, since it uses less digits than its factorization.

64400664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2683370 (or 2683366 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 64400664 is about 8025.0024299062. The cubic root of 64400664 is about 400.8329808199.

The spelling of 64400664 in words is "sixty-four million, four hundred thousand, six hundred sixty-four".