21311311986 has 36 divisors (see below), whose sum is σ = 48269404638. Its totient is φ = 6794908032.

The previous prime is 21311311969. The next prime is 21311311999. The reversal of 21311311986 is 68911311312.

It is a happy number.

21311311986 is a `hidden beast` number, since 21 + 311 + 311 + 9 + 8 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16559829225 + 4751482761 = 128685^2 + 68931^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21311311986.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1109535 + ... + 1128578.

Almost surely, 2^21311311986 is an apocalyptic number.

21311311986 is an abundant number, since it is smaller than the sum of its proper divisors (26958092652).

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

21311311986 is a wasteful number, since it uses less digits than its factorization.

21311311986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2238167 (or 2238141 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The spelling of 21311311986 in words is "twenty-one billion, three hundred eleven million, three hundred eleven thousand, nine hundred eighty-six".