21279998624 has 48 divisors (see below), whose sum is σ = 44157483720. Its totient is φ = 10079247360.

The previous prime is 21279998617. The next prime is 21279998629. The reversal of 21279998624 is 42689997212.

It can be written as a sum of positive squares in 4 ways, for example, as 18068736400 + 3211262224 = 134420^2 + 56668^2 .

It is not an unprimeable number, because it can be changed into a prime (21279998629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 167147 + ... + 265514.

Almost surely, 2^21279998624 is an apocalyptic number.

It is an amenable number.

21279998624 is an abundant number, since it is smaller than the sum of its proper divisors (22877485096).

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

21279998624 is a wasteful number, since it uses less digits than its factorization.

21279998624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432753 (or 432745 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 59.

The spelling of 21279998624 in words is "twenty-one billion, two hundred seventy-nine million, nine hundred ninety-eight thousand, six hundred twenty-four".