21180802686 has 16 divisors (see below), whose sum is σ = 42941902224. Its totient is φ = 6963551424.

The previous prime is 21180802679. The next prime is 21180802751. The reversal of 21180802686 is 68620808112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24178561 + ... + 24179436.

It is an arithmetic number, because the mean of its divisors is an integer number (2683868889).

Almost surely, 2^21180802686 is an apocalyptic number.

21180802686 is an abundant number, since it is smaller than the sum of its proper divisors (21761099538).

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

21180802686 is a wasteful number, since it uses less digits than its factorization.

21180802686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48358075.

The product of its (nonzero) digits is 73728, while the sum is 42.

It can be divided in two parts, 211808026 and 86, that added together give a palindrome (211808112).

The spelling of 21180802686 in words is "twenty-one billion, one hundred eighty million, eight hundred two thousand, six hundred eighty-six".