21445277472 has 120 divisors (see below), whose sum is σ = 63235071900. Its totient is φ = 7129714176.

The previous prime is 21445277459. The next prime is 21445277473. The reversal of 21445277472 is 27477254412.

21445277472 is a `hidden beast` number, since 21 + 44 + 52 + 77 + 472 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21247143696 + 198133776 = 145764^2 + 14076^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21445277473) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 997654 + ... + 1018922.

Almost surely, 2^21445277472 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 21445277472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31617535950).

21445277472 is an abundant number, since it is smaller than the sum of its proper divisors (41789794428).

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

21445277472 is a wasteful number, since it uses less digits than its factorization.

21445277472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21680 (or 21663 counting only the distinct ones).

The product of its digits is 878080, while the sum is 45.

The spelling of 21445277472 in words is "twenty-one billion, four hundred forty-five million, two hundred seventy-seven thousand, four hundred seventy-two".