644356053 has 24 divisors (see below), whose sum is σ = 1052958816. Its totient is φ = 390517200.

The previous prime is 644356043. The next prime is 644356057. The reversal of 644356053 is 350653446.

644356053 is a `hidden beast` number, since 6 + 4 + 43 + 5 + 605 + 3 = 666.

644356053 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644356053 - 2¹³ = 644347861 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644355999 and 644356017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644356057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117858 + ... + 123203.

It is an arithmetic number, because the mean of its divisors is an integer number (43873284).

Almost surely, 2^644356053 is an apocalyptic number.

It is an amenable number.

644356053 is a deficient number, since it is larger than the sum of its proper divisors (408602763).

644356053 is a wasteful number, since it uses less digits than its factorization.

644356053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241087 (or 241075 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 644356053 is about 25384.1693383888. The cubic root of 644356053 is about 863.7246301267.

The spelling of 644356053 in words is "six hundred forty-four million, three hundred fifty-six thousand, fifty-three".