21321311986 has 16 divisors (see below), whose sum is σ = 34764012864. Its totient is φ = 9748635984.

The previous prime is 21321311983. The next prime is 21321311993. The reversal of 21321311986 is 68911312312.

It is not an unprimeable number, because it can be changed into a prime (21321311981) 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, 3829230 + ... + 3834793.

It is an arithmetic number, because the mean of its divisors is an integer number (2172750804).

Almost surely, 2^21321311986 is an apocalyptic number.

21321311986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21321311986 is a deficient number, since it is larger than the sum of its proper divisors (13442700878).

21321311986 is a wasteful number, since it uses less digits than its factorization.

21321311986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7664145.

The product of its digits is 15552, while the sum is 37.

The spelling of 21321311986 in words is "twenty-one billion, three hundred twenty-one million, three hundred eleven thousand, nine hundred eighty-six".