6644623455 has 32 divisors (see below), whose sum is σ = 11817388800. Its totient is φ = 3542381856.

The previous prime is 6644623423. The next prime is 6644623457. The reversal of 6644623455 is 5543264466.

It is a happy number.

It is not a de Polignac number, because 6644623455 - 2⁵ = 6644623423 is a prime.

It is a super-2 number, since 2×6644623455² = 88302041717472274050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 6644623455.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6644623457) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 388392 + ... + 405138.

It is an arithmetic number, because the mean of its divisors is an integer number (369293400).

Almost surely, 2^6644623455 is an apocalyptic number.

6644623455 is a deficient number, since it is larger than the sum of its proper divisors (5172765345).

6644623455 is a wasteful number, since it uses less digits than its factorization.

6644623455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19700 (or 19694 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 45.

The square root of 6644623455 is about 81514.5597730859. The cubic root of 6644623455 is about 1879.9954216540.

The spelling of 6644623455 in words is "six billion, six hundred forty-four million, six hundred twenty-three thousand, four hundred fifty-five".