644421054 has 16 divisors (see below), whose sum is σ = 1303324560. Its totient is φ = 212393280.

The previous prime is 644421049. The next prime is 644421073. The reversal of 644421054 is 450124446.

It is a happy number.

It is a congruent number.

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, 602857 + ... + 603924.

It is an arithmetic number, because the mean of its divisors is an integer number (81457785).

Almost surely, 2^644421054 is an apocalyptic number.

644421054 is an abundant number, since it is smaller than the sum of its proper divisors (658903506).

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

644421054 is a wasteful number, since it uses less digits than its factorization.

644421054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206875.

The product of its (nonzero) digits is 15360, while the sum is 30.

The square root of 644421054 is about 25385.4496513259. The cubic root of 644421054 is about 863.7536725982.

The spelling of 644421054 in words is "six hundred forty-four million, four hundred twenty-one thousand, fifty-four".