21456769686 has 64 divisors (see below), whose sum is σ = 47996928000. Its totient is φ = 6338131200.

The previous prime is 21456769583. The next prime is 21456769687. The reversal of 21456769686 is 68696765412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21456769687) 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, 4189035 + ... + 4194153.

It is an arithmetic number, because the mean of its divisors is an integer number (749952000).

Almost surely, 2^21456769686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21456769686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23998464000).

21456769686 is an abundant number, since it is smaller than the sum of its proper divisors (26540158314).

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

21456769686 is a wasteful number, since it uses less digits than its factorization.

21456769686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6725.

The product of its digits is 26127360, while the sum is 60.

The spelling of 21456769686 in words is "twenty-one billion, four hundred fifty-six million, seven hundred sixty-nine thousand, six hundred eighty-six".