21814239 has 4 divisors (see below), whose sum is σ = 29085656. Its totient is φ = 14542824.

The previous prime is 21814237. The next prime is 21814241. The reversal of 21814239 is 93241812.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21814237) and next prime (21814241).

It is not a de Polignac number, because 21814239 - 2¹ = 21814237 is a prime.

It is a super-2 number, since 2×21814239² = 951722046298242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21814231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3635704 + ... + 3635709.

It is an arithmetic number, because the mean of its divisors is an integer number (7271414).

Almost surely, 2^21814239 is an apocalyptic number.

21814239 is a deficient number, since it is larger than the sum of its proper divisors (7271417).

21814239 is an equidigital number, since it uses as much as digits as its factorization.

21814239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7271416.

The product of its digits is 3456, while the sum is 30.

The square root of 21814239 is about 4670.5715924285. The cubic root of 21814239 is about 279.4130519365.

The spelling of 21814239 in words is "twenty-one million, eight hundred fourteen thousand, two hundred thirty-nine".