644422722 has 16 divisors (see below), whose sum is σ = 1292563872. Its totient is φ = 214187840.

The previous prime is 644422711. The next prime is 644422741. The reversal of 644422722 is 227224446.

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, 152679 + ... + 156842.

It is an arithmetic number, because the mean of its divisors is an integer number (80785242).

Almost surely, 2^644422722 is an apocalyptic number.

644422722 is an abundant number, since it is smaller than the sum of its proper divisors (648141150).

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

644422722 is a wasteful number, since it uses less digits than its factorization.

644422722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309873.

The product of its digits is 43008, while the sum is 33.

The square root of 644422722 is about 25385.4825047703. The cubic root of 644422722 is about 863.7544178356.

The spelling of 644422722 in words is "six hundred forty-four million, four hundred twenty-two thousand, seven hundred twenty-two".