21808836532 has 48 divisors (see below), whose sum is σ = 45534327552. Its totient is φ = 8936294400.

The previous prime is 21808836527. The next prime is 21808836589. The reversal of 21808836532 is 23563880812.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1766782 + ... + 1779082.

It is an arithmetic number, because the mean of its divisors is an integer number (948631824).

Almost surely, 2^21808836532 is an apocalyptic number.

It is an amenable number.

21808836532 is an abundant number, since it is smaller than the sum of its proper divisors (23725491020).

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

21808836532 is a wasteful number, since it uses less digits than its factorization.

21808836532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15088 (or 15086 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 21808836532 in words is "twenty-one billion, eight hundred eight million, eight hundred thirty-six thousand, five hundred thirty-two".