644050051 has 4 divisors (see below), whose sum is σ = 644653600. Its totient is φ = 643446504.

The previous prime is 644050031. The next prime is 644050061. The reversal of 644050051 is 150050446.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 644050051 - 2¹³ = 644041859 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644049998 and 644050025.

It is not an unprimeable number, because it can be changed into a prime (644050021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 300171 + ... + 302308.

It is an arithmetic number, because the mean of its divisors is an integer number (161163400).

Almost surely, 2^644050051 is an apocalyptic number.

644050051 is a deficient number, since it is larger than the sum of its proper divisors (603549).

644050051 is a wasteful number, since it uses less digits than its factorization.

644050051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603548.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 644050051 is about 25378.1412045879. The cubic root of 644050051 is about 863.5878820702.

The spelling of 644050051 in words is "six hundred forty-four million, fifty thousand, fifty-one".