21959373 has 4 divisors (see below), whose sum is σ = 29279168. Its totient is φ = 14639580.

The previous prime is 21959341. The next prime is 21959407. The reversal of 21959373 is 37395912.

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 not a de Polignac number, because 21959373 - 2⁵ = 21959341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21959303) 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, 3659893 + ... + 3659898.

It is an arithmetic number, because the mean of its divisors is an integer number (7319792).

Almost surely, 2^21959373 is an apocalyptic number.

It is an amenable number.

21959373 is a deficient number, since it is larger than the sum of its proper divisors (7319795).

21959373 is an equidigital number, since it uses as much as digits as its factorization.

21959373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7319794.

The product of its digits is 51030, while the sum is 39.

The square root of 21959373 is about 4686.0829057967. The cubic root of 21959373 is about 280.0313442802.

The spelling of 21959373 in words is "twenty-one million, nine hundred fifty-nine thousand, three hundred seventy-three".