21932891 has 4 divisors (see below), whose sum is σ = 21942792. Its totient is φ = 21922992.

The previous prime is 21932887. The next prime is 21932899. The reversal of 21932891 is 19823912.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21932891 - 2² = 21932887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21932899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (5485698).

Almost surely, 2^21932891 is an apocalyptic number.

21932891 is a deficient number, since it is larger than the sum of its proper divisors (9901).

21932891 is an equidigital number, since it uses as much as digits as its factorization.

21932891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9900.

The product of its digits is 7776, while the sum is 35.

The square root of 21932891 is about 4683.2564525125. The cubic root of 21932891 is about 279.9187306658.

The spelling of 21932891 in words is "twenty-one million, nine hundred thirty-two thousand, eight hundred ninety-one".