21321312999 has 32 divisors (see below), whose sum is σ = 32772096000. Its totient is φ = 12077943264.

The previous prime is 21321312989. The next prime is 21321313061. The reversal of 21321312999 is 99921312312.

It is not a de Polignac number, because 21321312999 - 2⁴ = 21321312983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21321312999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321312989) 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, 2093682 + ... + 2103840.

It is an arithmetic number, because the mean of its divisors is an integer number (1024128000).

Almost surely, 2^21321312999 is an apocalyptic number.

21321312999 is a deficient number, since it is larger than the sum of its proper divisors (11450783001).

21321312999 is a wasteful number, since it uses less digits than its factorization.

21321312999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11027.

The product of its digits is 52488, while the sum is 42.

It can be divided in two parts, 2132 and 1312999, that added together give a palindrome (1315131).

The spelling of 21321312999 in words is "twenty-one billion, three hundred twenty-one million, three hundred twelve thousand, nine hundred ninety-nine".