21089312 has 24 divisors (see below), whose sum is σ = 41622336. Its totient is φ = 10518592.

The previous prime is 21089291. The next prime is 21089359. The reversal of 21089312 is 21398012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23333 + ... + 24219.

It is an arithmetic number, because the mean of its divisors is an integer number (1734264).

Almost surely, 2^21089312 is an apocalyptic number.

It is an amenable number.

21089312 is a deficient number, since it is larger than the sum of its proper divisors (20533024).

21089312 is an equidigital number, since it uses as much as digits as its factorization.

21089312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640 (or 1632 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21089312 is about 4592.3100940594. The cubic root of 21089312 is about 276.2829835790.

The spelling of 21089312 in words is "twenty-one million, eighty-nine thousand, three hundred twelve".