21151316736 has 108 divisors (see below), whose sum is σ = 66528582120. Its totient is φ = 6409482240.

The previous prime is 21151316731. The next prime is 21151316737. The reversal of 21151316736 is 63761315112.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21151316736.

It is not an unprimeable number, because it can be changed into a prime (21151316731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 391941 + ... + 442628.

It is an arithmetic number, because the mean of its divisors is an integer number (616005390).

Almost surely, 2^21151316736 is an apocalyptic number.

It is an amenable number.

21151316736 is an abundant number, since it is smaller than the sum of its proper divisors (45377265384).

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

21151316736 is a wasteful number, since it uses less digits than its factorization.

21151316736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834602 (or 834585 counting only the distinct ones).

The product of its digits is 22680, while the sum is 36.

The spelling of 21151316736 in words is "twenty-one billion, one hundred fifty-one million, three hundred sixteen thousand, seven hundred thirty-six".