644644062 has 32 divisors (see below), whose sum is σ = 1433372160. Its totient is φ = 214756920.

The previous prime is 644644061. The next prime is 644644079. The reversal of 644644062 is 260446446.

It is a happy number.

644644062 is a `hidden beast` number, since 6 + 4 + 4 + 644 + 0 + 6 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644644061) 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, 178737 + ... + 182307.

It is an arithmetic number, because the mean of its divisors is an integer number (44792880).

Almost surely, 2^644644062 is an apocalyptic number.

644644062 is an abundant number, since it is smaller than the sum of its proper divisors (788728098).

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

644644062 is a wasteful number, since it uses less digits than its factorization.

644644062 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6925 (or 6919 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The square root of 644644062 is about 25389.8417088410. The cubic root of 644644062 is about 863.8532978160.

The spelling of 644644062 in words is "six hundred forty-four million, six hundred forty-four thousand, sixty-two".