21932121 has 4 divisors (see below), whose sum is σ = 29242832. Its totient is φ = 14621412.

The previous prime is 21932077. The next prime is 21932143. The reversal of 21932121 is 12123912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-21932121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21932161) 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, 3655351 + ... + 3655356.

It is an arithmetic number, because the mean of its divisors is an integer number (7310708).

Almost surely, 2^21932121 is an apocalyptic number.

It is an amenable number.

21932121 is a deficient number, since it is larger than the sum of its proper divisors (7310711).

21932121 is an equidigital number, since it uses as much as digits as its factorization.

21932121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7310710.

The product of its digits is 216, while the sum is 21.

The square root of 21932121 is about 4683.1742440358. The cubic root of 21932121 is about 279.9154549166.

The spelling of 21932121 in words is "twenty-one million, nine hundred thirty-two thousand, one hundred twenty-one".