664426660 has 12 divisors (see below), whose sum is σ = 1395296028. Its totient is φ = 265770656.

The previous prime is 664426643. The next prime is 664426673. The reversal of 664426660 is 66624466.

It can be written as a sum of positive squares in 2 ways, for example, as 151585344 + 512841316 = 12312^2 + 22646^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16610647 + ... + 16610686.

It is an arithmetic number, because the mean of its divisors is an integer number (116274669).

Almost surely, 2^664426660 is an apocalyptic number.

It is an amenable number.

664426660 is an abundant number, since it is smaller than the sum of its proper divisors (730869368).

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

664426660 is a wasteful number, since it uses less digits than its factorization.

664426660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33221342 (or 33221340 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 40.

The square root of 664426660 is about 25776.4749335513. The cubic root of 664426660 is about 872.6009538279.

The spelling of 664426660 in words is "six hundred sixty-four million, four hundred twenty-six thousand, six hundred sixty".