644466066 has 32 divisors (see below), whose sum is σ = 1300947648. Its totient is φ = 212829120.

The previous prime is 644466047. The next prime is 644466079. The reversal of 644466066 is 660664446.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 332436 + ... + 334368.

It is an arithmetic number, because the mean of its divisors is an integer number (40654614).

Almost surely, 2^644466066 is an apocalyptic number.

644466066 is an abundant number, since it is smaller than the sum of its proper divisors (656481582).

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

644466066 is a wasteful number, since it uses less digits than its factorization.

644466066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2426.

The product of its (nonzero) digits is 497664, while the sum is 42.

The square root of 644466066 is about 25386.3362067077. The cubic root of 644466066 is about 863.7737828325.

The spelling of 644466066 in words is "six hundred forty-four million, four hundred sixty-six thousand, sixty-six".