20644044447 has 32 divisors (see below), whose sum is σ = 29793254400. Its totient is φ = 12639699072.

The previous prime is 20644044433. The next prime is 20644044479. The reversal of 20644044447 is 74444044602.

It is not a de Polignac number, because 20644044447 - 2⁶ = 20644044383 is a prime.

It is a super-2 number, since 2×20644044447² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20644044347) 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, 7022704 + ... + 7025642.

It is an arithmetic number, because the mean of its divisors is an integer number (931039200).

Almost surely, 2^20644044447 is an apocalyptic number.

20644044447 is a deficient number, since it is larger than the sum of its proper divisors (9149209953).

20644044447 is a wasteful number, since it uses less digits than its factorization.

20644044447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3807.

The product of its (nonzero) digits is 344064, while the sum is 39.

The spelling of 20644044447 in words is "twenty billion, six hundred forty-four million, forty-four thousand, four hundred forty-seven".