21911323 has 8 divisors (see below), whose sum is σ = 25083648. Its totient is φ = 18749544.

The previous prime is 21911321. The next prime is 21911333. The reversal of 21911323 is 32311912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21911323 - 2¹ = 21911321 is a prime.

It is a super-2 number, since 2×21911323² = 960212151220658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21911294 and 21911303.

It is not an unprimeable number, because it can be changed into a prime (21911321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2490 + ... + 7072.

It is an arithmetic number, because the mean of its divisors is an integer number (3135456).

Almost surely, 2^21911323 is an apocalyptic number.

21911323 is a deficient number, since it is larger than the sum of its proper divisors (3172325).

21911323 is an equidigital number, since it uses as much as digits as its factorization.

21911323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273.

The product of its digits is 324, while the sum is 22.

The square root of 21911323 is about 4680.9532148912. The cubic root of 21911323 is about 279.8269466382.

The spelling of 21911323 in words is "twenty-one million, nine hundred eleven thousand, three hundred twenty-three".