21937193 has 4 divisors (see below), whose sum is σ = 22891008. Its totient is φ = 20983380.

The previous prime is 21937187. The next prime is 21937213. The reversal of 21937193 is 39173912.

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 cyclic number.

It is not a de Polignac number, because 21937193 - 2²⁰ = 20888617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21937133) 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, 476873 + ... + 476918.

It is an arithmetic number, because the mean of its divisors is an integer number (5722752).

Almost surely, 2^21937193 is an apocalyptic number.

21937193 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21937193 is a deficient number, since it is larger than the sum of its proper divisors (953815).

21937193 is an equidigital number, since it uses as much as digits as its factorization.

21937193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953814.

The product of its digits is 10206, while the sum is 35.

The square root of 21937193 is about 4683.7157257887. The cubic root of 21937193 is about 279.9370309080.

The spelling of 21937193 in words is "twenty-one million, nine hundred thirty-seven thousand, one hundred ninety-three".