21896239 has 2 divisors, whose sum is σ = 21896240. Its totient is φ = 21896238.

The previous prime is 21896213. The next prime is 21896249. The reversal of 21896239 is 93269812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21896239 - 2²³ = 13507631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21896209) 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 as a sum of consecutive naturals, namely, 10948119 + 10948120.

It is an arithmetic number, because the mean of its divisors is an integer number (10948120).

Almost surely, 2^21896239 is an apocalyptic number.

21896239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21896239 is an equidigital number, since it uses as much as digits as its factorization.

21896239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 40.

The square root of 21896239 is about 4679.3417272091. The cubic root of 21896239 is about 279.7627198971.

The spelling of 21896239 in words is "twenty-one million, eight hundred ninety-six thousand, two hundred thirty-nine".