21469919 has 2 divisors, whose sum is σ = 21469920. Its totient is φ = 21469918.

The previous prime is 21469901. The next prime is 21469927. The reversal of 21469919 is 91996412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21469919 - 2¹² = 21465823 is a prime.

It is a super-2 number, since 2×21469919² = 921914843733122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21469939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10734959 + 10734960.

It is an arithmetic number, because the mean of its divisors is an integer number (10734960).

Almost surely, 2^21469919 is an apocalyptic number.

21469919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21469919 is an equidigital number, since it uses as much as digits as its factorization.

21469919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 41.

The square root of 21469919 is about 4633.5643947182. The cubic root of 21469919 is about 277.9351460951.

The spelling of 21469919 in words is "twenty-one million, four hundred sixty-nine thousand, nine hundred nineteen".