21091832 has 16 divisors (see below), whose sum is σ = 41873760. Its totient is φ = 9925504.

The previous prime is 21091823. The next prime is 21091841. The reversal of 21091832 is 23819012.

It is an interprime number because it is at equal distance from previous prime (21091823) and next prime (21091841).

It is a congruent number.

It is an unprimeable number.

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, 77408 + ... + 77679.

It is an arithmetic number, because the mean of its divisors is an integer number (2617110).

Almost surely, 2^21091832 is an apocalyptic number.

It is an amenable number.

21091832 is a deficient number, since it is larger than the sum of its proper divisors (20781928).

21091832 is a wasteful number, since it uses less digits than its factorization.

21091832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155110 (or 155106 counting only the distinct ones).

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

The square root of 21091832 is about 4592.5844575794. The cubic root of 21091832 is about 276.2939876584.

The spelling of 21091832 in words is "twenty-one million, ninety-one thousand, eight hundred thirty-two".