644109433 has 8 divisors (see below), whose sum is σ = 703225440. Its totient is φ = 585086880.

The previous prime is 644109407. The next prime is 644109439. The reversal of 644109433 is 334901446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644109433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644109439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8535 + ... + 36892.

It is an arithmetic number, because the mean of its divisors is an integer number (87903180).

Almost surely, 2^644109433 is an apocalyptic number.

It is an amenable number.

644109433 is a deficient number, since it is larger than the sum of its proper divisors (59116007).

644109433 is a wasteful number, since it uses less digits than its factorization.

644109433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46727.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 644109433 is about 25379.3111214627. The cubic root of 644109433 is about 863.6144224504.

The spelling of 644109433 in words is "six hundred forty-four million, one hundred nine thousand, four hundred thirty-three".