21845239 has 8 divisors (see below), whose sum is σ = 24548832. Its totient is φ = 19287840.

The previous prime is 21845237. The next prime is 21845249. The reversal of 21845239 is 93254812.

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

It is not a de Polignac number, because 21845239 - 2¹ = 21845237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21845233) 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, 36232 + ... + 36829.

It is an arithmetic number, because the mean of its divisors is an integer number (3068604).

Almost surely, 2^21845239 is an apocalyptic number.

21845239 is a deficient number, since it is larger than the sum of its proper divisors (2703593).

21845239 is a wasteful number, since it uses less digits than its factorization.

21845239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73097.

The product of its digits is 17280, while the sum is 34.

The square root of 21845239 is about 4673.8890658637. The cubic root of 21845239 is about 279.5453463334.

The spelling of 21845239 in words is "twenty-one million, eight hundred forty-five thousand, two hundred thirty-nine".