21811608084 has 24 divisors (see below), whose sum is σ = 58164288448. Its totient is φ = 6231888000.

The previous prime is 21811608067. The next prime is 21811608187. The reversal of 21811608084 is 48080611812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129830917 + ... + 129831084.

Almost surely, 2^21811608084 is an apocalyptic number.

It is an amenable number.

21811608084 is an abundant number, since it is smaller than the sum of its proper divisors (36352680364).

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

21811608084 is a wasteful number, since it uses less digits than its factorization.

21811608084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259662015 (or 259662013 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 39.

The spelling of 21811608084 in words is "twenty-one billion, eight hundred eleven million, six hundred eight thousand, eighty-four".