21159992 has 32 divisors (see below), whose sum is σ = 45926400. Its totient is φ = 8951904.

The previous prime is 21159973. The next prime is 21160001. The reversal of 21159992 is 29995112.

It is a super-2 number, since 2×21159992² = 895490522880128, which contains 22 as substring.

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, 2033 + ... + 6815.

It is an arithmetic number, because the mean of its divisors is an integer number (1435200).

Almost surely, 2^21159992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21159992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22963200).

21159992 is an abundant number, since it is smaller than the sum of its proper divisors (24766408).

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

21159992 is a wasteful number, since it uses less digits than its factorization.

21159992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4875 (or 4871 counting only the distinct ones).

The product of its digits is 14580, while the sum is 38.

The square root of 21159992 is about 4599.9991304347. Note that the first 3 decimals coincide. The cubic root of 21159992 is about 276.5912899285.

The spelling of 21159992 in words is "twenty-one million, one hundred fifty-nine thousand, nine hundred ninety-two".