644420602 has 32 divisors (see below), whose sum is σ = 1122750720. Its totient is φ = 271708800.

The previous prime is 644420573. The next prime is 644420603. The reversal of 644420602 is 206024446.

It is not an unprimeable number, because it can be changed into a prime (644420603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234774 + ... + 237502.

It is an arithmetic number, because the mean of its divisors is an integer number (35085960).

Almost surely, 2^644420602 is an apocalyptic number.

644420602 is a deficient number, since it is larger than the sum of its proper divisors (478330118).

644420602 is a wasteful number, since it uses less digits than its factorization.

644420602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3006.

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 644420602 is about 25385.4407485866. The cubic root of 644420602 is about 863.7534706512.

The spelling of 644420602 in words is "six hundred forty-four million, four hundred twenty thousand, six hundred two".