21609892 has 12 divisors (see below), whose sum is σ = 37897776. Its totient is φ = 10781960.

The previous prime is 21609881. The next prime is 21609893. The reversal of 21609892 is 29890612.

It is not an unprimeable number, because it can be changed into a prime (21609893) 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 3 ways as a sum of consecutive naturals, for example, 3538 + ... + 7465.

It is an arithmetic number, because the mean of its divisors is an integer number (3158148).

Almost surely, 2^21609892 is an apocalyptic number.

It is an amenable number.

21609892 is a deficient number, since it is larger than the sum of its proper divisors (16287884).

21609892 is a wasteful number, since it uses less digits than its factorization.

21609892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11498 (or 11496 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 21609892 is about 4648.6441033919. The cubic root of 21609892 is about 278.5378370440.

The spelling of 21609892 in words is "twenty-one million, six hundred nine thousand, eight hundred ninety-two".