644131051 has 8 divisors (see below), whose sum is σ = 667699200. Its totient is φ = 620737320.

The previous prime is 644130979. The next prime is 644131057. The reversal of 644131051 is 150131446.

644131051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 644131051 - 2²⁵ = 610576619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644131057) 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, 36061 + ... + 50878.

It is an arithmetic number, because the mean of its divisors is an integer number (83462400).

Almost surely, 2^644131051 is an apocalyptic number.

644131051 is a deficient number, since it is larger than the sum of its proper divisors (23568149).

644131051 is a wasteful number, since it uses less digits than its factorization.

644131051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87209.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 644131051 is about 25379.7370159740. The cubic root of 644131051 is about 863.6240840631.

Adding to 644131051 its reverse (150131446), we get a palindrome (794262497).

The spelling of 644131051 in words is "six hundred forty-four million, one hundred thirty-one thousand, fifty-one".