21326369 has 4 divisors (see below), whose sum is σ = 21396144. Its totient is φ = 21256596.

The previous prime is 21326363. The next prime is 21326387. The reversal of 21326369 is 96362312.

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 21326369 - 2²⁰ = 20277793 is a prime.

It is a super-2 number, since 2×21326369² = 909628029448322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21326363) 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, 34427 + ... + 35040.

It is an arithmetic number, because the mean of its divisors is an integer number (5349036).

Almost surely, 2^21326369 is an apocalyptic number.

It is an amenable number.

21326369 is a deficient number, since it is larger than the sum of its proper divisors (69775).

21326369 is an equidigital number, since it uses as much as digits as its factorization.

21326369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69774.

The product of its digits is 11664, while the sum is 32.

The square root of 21326369 is about 4618.0481807794. The cubic root of 21326369 is about 277.3143264616.

The spelling of 21326369 in words is "twenty-one million, three hundred twenty-six thousand, three hundred sixty-nine".