644050053 has 6 divisors (see below), whose sum is σ = 930294534. Its totient is φ = 429366696.

The previous prime is 644050031. The next prime is 644050061. The reversal of 644050053 is 350050446.

It can be written as a sum of positive squares in only one way, i.e., 441756324 + 202293729 = 21018^2 + 14223^2 .

It is not a de Polignac number, because 644050053 - 2⁵ = 644050021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644049999 and 644050026.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644050003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35780550 + ... + 35780567.

It is an arithmetic number, because the mean of its divisors is an integer number (155049089).

Almost surely, 2^644050053 is an apocalyptic number.

It is an amenable number.

644050053 is a deficient number, since it is larger than the sum of its proper divisors (286244481).

644050053 is a wasteful number, since it uses less digits than its factorization.

644050053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71561123 (or 71561120 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

The square root of 644050053 is about 25378.1412439918. The cubic root of 644050053 is about 863.5878829641.

The spelling of 644050053 in words is "six hundred forty-four million, fifty thousand, fifty-three".