644530053 has 16 divisors (see below), whose sum is σ = 881745920. Its totient is φ = 418554864.

The previous prime is 644530049. The next prime is 644530057. The reversal of 644530053 is 350035446.

It is an interprime number because it is at equal distance from previous prime (644530049) and next prime (644530057).

It is not a de Polignac number, because 644530053 - 2² = 644530049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644530053.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644530057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42300 + ... + 55482.

It is an arithmetic number, because the mean of its divisors is an integer number (55109120).

Almost surely, 2^644530053 is an apocalyptic number.

It is an amenable number.

644530053 is a deficient number, since it is larger than the sum of its proper divisors (237215867).

644530053 is a wasteful number, since it uses less digits than its factorization.

644530053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13608.

The product of its (nonzero) digits is 21600, while the sum is 30.

The square root of 644530053 is about 25387.5964399941. The cubic root of 644530053 is about 863.8023690100.

Adding to 644530053 its reverse (350035446), we get a palindrome (994565499).

The spelling of 644530053 in words is "six hundred forty-four million, five hundred thirty thousand, fifty-three".