21790912 has 56 divisors (see below), whose sum is σ = 50822352. Its totient is φ = 9139200.

The previous prime is 21790843. The next prime is 21790921. The reversal of 21790912 is 21909712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7962 + ... + 10342.

It is an arithmetic number, because the mean of its divisors is an integer number (907542).

Almost surely, 2^21790912 is an apocalyptic number.

21790912 is a gapful number since it is divisible by the number (22) 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 21790912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25411176).

21790912 is an abundant number, since it is smaller than the sum of its proper divisors (29031440).

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

21790912 is a wasteful number, since it uses less digits than its factorization.

21790912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417 (or 2407 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 21790912 is about 4668.0736926488. The cubic root of 21790912 is about 279.3134198730.

The spelling of 21790912 in words is "twenty-one million, seven hundred ninety thousand, nine hundred twelve".