644097496 has 32 divisors (see below), whose sum is σ = 1461399840. Its totient is φ = 259803648.

The previous prime is 644097491. The next prime is 644097527. The reversal of 644097496 is 694790446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644097491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 337335 + ... + 339238.

It is an arithmetic number, because the mean of its divisors is an integer number (45668745).

Almost surely, 2^644097496 is an apocalyptic number.

It is an amenable number.

644097496 is an abundant number, since it is smaller than the sum of its proper divisors (817302344).

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

644097496 is a wasteful number, since it uses less digits than its factorization.

644097496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676603 (or 676599 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 49.

The square root of 644097496 is about 25379.0759485053. The cubic root of 644097496 is about 863.6090874206.

The spelling of 644097496 in words is "six hundred forty-four million, ninety-seven thousand, four hundred ninety-six".