21468919 has 2 divisors, whose sum is σ = 21468920. Its totient is φ = 21468918.

The previous prime is 21468907. The next prime is 21468929. The reversal of 21468919 is 91986412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21468919 - 2⁷ = 21468791 is a prime.

It is a super-2 number, since 2×21468919² = 921828966057122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21468929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10734459 + 10734460.

It is an arithmetic number, because the mean of its divisors is an integer number (10734460).

Almost surely, 2^21468919 is an apocalyptic number.

21468919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21468919 is an equidigital number, since it uses as much as digits as its factorization.

21468919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 21468919 is about 4633.4564851739. The cubic root of 21468919 is about 277.9308309187.

The spelling of 21468919 in words is "twenty-one million, four hundred sixty-eight thousand, nine hundred nineteen".