21992431608 has 128 divisors (see below), whose sum is σ = 70470259200. Its totient is φ = 6224781312.

The previous prime is 21992431589. The next prime is 21992431613. The reversal of 21992431608 is 80613429912.

21992431608 is a `hidden beast` number, since 2 + 1 + 9 + 9 + 2 + 4 + 31 + 608 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 93816 + ... + 229752.

It is an arithmetic number, because the mean of its divisors is an integer number (550548900).

Almost surely, 2^21992431608 is an apocalyptic number.

21992431608 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21992431608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35235129600).

21992431608 is an abundant number, since it is smaller than the sum of its proper divisors (48477827592).

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

21992431608 is a wasteful number, since it uses less digits than its factorization.

21992431608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136066 (or 136056 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 21992431608 in words is "twenty-one billion, nine hundred ninety-two million, four hundred thirty-one thousand, six hundred eight".