644614692 has 24 divisors (see below), whose sum is σ = 1509658752. Its totient is φ = 214077600.

The previous prime is 644614681. The next prime is 644614693. The reversal of 644614692 is 296416446.

It is a super-2 number, since 2×644614692² = 831056202284509728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644614693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95859 + ... + 102362.

It is an arithmetic number, because the mean of its divisors is an integer number (62902448).

Almost surely, 2^644614692 is an apocalyptic number.

It is an amenable number.

644614692 is an abundant number, since it is smaller than the sum of its proper divisors (865044060).

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

644614692 is a wasteful number, since it uses less digits than its factorization.

644614692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198499 (or 198497 counting only the distinct ones).

The product of its digits is 248832, while the sum is 42.

The square root of 644614692 is about 25389.2633213333. The cubic root of 644614692 is about 863.8401785573.

The spelling of 644614692 in words is "six hundred forty-four million, six hundred fourteen thousand, six hundred ninety-two".