21576937564 has 96 divisors (see below), whose sum is σ = 48118784000. Its totient is φ = 8235406080.

The previous prime is 21576937561. The next prime is 21576937579. The reversal of 21576937564 is 46573967512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21576937561) 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, 3935377 + ... + 3940855.

Almost surely, 2^21576937564 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 21576937564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24059392000).

21576937564 is an abundant number, since it is smaller than the sum of its proper divisors (26541846436).

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

21576937564 is a wasteful number, since it uses less digits than its factorization.

21576937564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5883 (or 5881 counting only the distinct ones).

The product of its digits is 9525600, while the sum is 55.

The spelling of 21576937564 in words is "twenty-one billion, five hundred seventy-six million, nine hundred thirty-seven thousand, five hundred sixty-four".