21444778592 has 96 divisors (see below), whose sum is σ = 43666983360. Its totient is φ = 10362193920.

The previous prime is 21444778591. The next prime is 21444778601. The reversal of 21444778592 is 29587744412.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444778591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57492518 + ... + 57492890.

It is an arithmetic number, because the mean of its divisors is an integer number (454864410).

Almost surely, 2^21444778592 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21444778592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21833491680).

21444778592 is an abundant number, since it is smaller than the sum of its proper divisors (22222204768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21444778592 is a wasteful number, since it uses less digits than its factorization.

21444778592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 848 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 53.

The spelling of 21444778592 in words is "twenty-one billion, four hundred forty-four million, seven hundred seventy-eight thousand, five hundred ninety-two".