21913373 has 4 divisors (see below), whose sum is σ = 22620288. Its totient is φ = 21206460.

The previous prime is 21913363. The next prime is 21913379. The reversal of 21913373 is 37331912.

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 21913373 - 2⁸ = 21913117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21913379) 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, 353411 + ... + 353472.

It is an arithmetic number, because the mean of its divisors is an integer number (5655072).

Almost surely, 2^21913373 is an apocalyptic number.

It is an amenable number.

21913373 is a deficient number, since it is larger than the sum of its proper divisors (706915).

21913373 is an equidigital number, since it uses as much as digits as its factorization.

21913373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706914.

The product of its digits is 3402, while the sum is 29.

The square root of 21913373 is about 4681.1721822638. The cubic root of 21913373 is about 279.8356731363.

The spelling of 21913373 in words is "twenty-one million, nine hundred thirteen thousand, three hundred seventy-three".