21989479953 has 96 divisors (see below), whose sum is σ = 36345388800. Its totient is φ = 11811744000.

The previous prime is 21989479951. The next prime is 21989480039. The reversal of 21989479953 is 35997498912.

It is not a de Polignac number, because 21989479953 - 2¹ = 21989479951 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21989479951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 36587853 + ... + 36588453.

It is an arithmetic number, because the mean of its divisors is an integer number (378597800).

Almost surely, 2^21989479953 is an apocalyptic number.

It is an amenable number.

21989479953 is a deficient number, since it is larger than the sum of its proper divisors (14355908847).

21989479953 is an equidigital number, since it uses as much as digits as its factorization.

21989479953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724 (or 679 counting only the distinct ones).

The product of its digits is 44089920, while the sum is 66.

The spelling of 21989479953 in words is "twenty-one billion, nine hundred eighty-nine million, four hundred seventy-nine thousand, nine hundred fifty-three".