21591892 has 24 divisors (see below), whose sum is σ = 44674560. Its totient is φ = 8934240.

The previous prime is 21591839. The next prime is 21591893. The reversal of 21591892 is 29819512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21591893) by changing a digit.

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, 12484 + ... + 14107.

It is an arithmetic number, because the mean of its divisors is an integer number (1861440).

Almost surely, 2^21591892 is an apocalyptic number.

It is an amenable number.

21591892 is an abundant number, since it is smaller than the sum of its proper divisors (23082668).

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

21591892 is a wasteful number, since it uses less digits than its factorization.

21591892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26631 (or 26629 counting only the distinct ones).

The product of its digits is 12960, while the sum is 37.

The square root of 21591892 is about 4646.7076516605. The cubic root of 21591892 is about 278.4604793574.

The spelling of 21591892 in words is "twenty-one million, five hundred ninety-one thousand, eight hundred ninety-two".