644516051 has 8 divisors (see below), whose sum is σ = 681753120. Its totient is φ = 608046912.

The previous prime is 644516027. The next prime is 644516069. The reversal of 644516051 is 150615446.

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-644516051 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644515999 and 644516017.

It is not an unprimeable number, because it can be changed into a prime (644516251) 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, 190256 + ... + 193613.

It is an arithmetic number, because the mean of its divisors is an integer number (85219140).

Almost surely, 2^644516051 is an apocalyptic number.

644516051 is a deficient number, since it is larger than the sum of its proper divisors (37237069).

644516051 is a wasteful number, since it uses less digits than its factorization.

644516051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383965.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 644516051 is about 25387.3206739112. The cubic root of 644516051 is about 863.7961137814.

The spelling of 644516051 in words is "six hundred forty-four million, five hundred sixteen thousand, fifty-one".