644472535 has 16 divisors (see below), whose sum is σ = 922277376. Its totient is φ = 422709408.

The previous prime is 644472511. The next prime is 644472541. The reversal of 644472535 is 535274446.

It is a cyclic number.

It is not a de Polignac number, because 644472535 - 2¹¹ = 644470487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399489 + ... + 401098.

It is an arithmetic number, because the mean of its divisors is an integer number (57642336).

Almost surely, 2^644472535 is an apocalyptic number.

644472535 is a deficient number, since it is larger than the sum of its proper divisors (277804841).

644472535 is a wasteful number, since it uses less digits than its factorization.

644472535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800622.

The product of its digits is 403200, while the sum is 40.

The square root of 644472535 is about 25386.4636174478. The cubic root of 644472535 is about 863.7766729427.

The spelling of 644472535 in words is "six hundred forty-four million, four hundred seventy-two thousand, five hundred thirty-five".