664321610 has 16 divisors (see below), whose sum is σ = 1218341736. Its totient is φ = 260714688.

The previous prime is 664321607. The next prime is 664321639. The reversal of 664321610 is 16123466.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 502701241 + 161620369 = 22421^2 + 12713^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 626189 + ... + 627248.

Almost surely, 2^664321610 is an apocalyptic number.

664321610 is a deficient number, since it is larger than the sum of its proper divisors (554020126).

664321610 is a wasteful number, since it uses less digits than its factorization.

664321610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253497.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 664321610 is about 25774.4371422540. The cubic root of 664321610 is about 872.5549635191.

The spelling of 664321610 in words is "six hundred sixty-four million, three hundred twenty-one thousand, six hundred ten".