21573320844 has 24 divisors (see below), whose sum is σ = 50341838848. Its totient is φ = 7190522640.

The previous prime is 21573320809. The next prime is 21573320849. The reversal of 21573320844 is 44802337512.

It is not an unprimeable number, because it can be changed into a prime (21573320849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96549 + ... + 229059.

Almost surely, 2^21573320844 is an apocalyptic number.

It is an amenable number.

21573320844 is an abundant number, since it is smaller than the sum of its proper divisors (28768518004).

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

21573320844 is a wasteful number, since it uses less digits than its factorization.

21573320844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146085 (or 146083 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 39.

The spelling of 21573320844 in words is "twenty-one billion, five hundred seventy-three million, three hundred twenty thousand, eight hundred forty-four".