21321013012 has 48 divisors (see below), whose sum is σ = 42780930192. Its totient is φ = 9210378240.

The previous prime is 21321012989. The next prime is 21321013033. The reversal of 21321013012 is 21031012312.

It can be written as a sum of positive squares in 8 ways, for example, as 326741776 + 20994271236 = 18076^2 + 144894^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93378 + ... + 226630.

It is an arithmetic number, because the mean of its divisors is an integer number (891269379).

Almost surely, 2^21321013012 is an apocalyptic number.

It is an amenable number.

21321013012 is an abundant number, since it is smaller than the sum of its proper divisors (21459917180).

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

21321013012 is a wasteful number, since it uses less digits than its factorization.

21321013012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133468 (or 133466 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21321013012 its reverse (21031012312), we get a palindrome (42352025324).

The spelling of 21321013012 in words is "twenty-one billion, three hundred twenty-one million, thirteen thousand, twelve".