20442239 has 4 divisors (see below), whose sum is σ = 21331056. Its totient is φ = 19553424.

The previous prime is 20442203. The next prime is 20442269. The reversal of 20442239 is 93224402.

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

It is a cyclic number.

It is not a de Polignac number, because 20442239 - 2⁸ = 20441983 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 (20442269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444374 + ... + 444419.

It is an arithmetic number, because the mean of its divisors is an integer number (5332764).

Almost surely, 2^20442239 is an apocalyptic number.

20442239 is a deficient number, since it is larger than the sum of its proper divisors (888817).

20442239 is an equidigital number, since it uses as much as digits as its factorization.

20442239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888816.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 20442239 is about 4521.3094342237. The cubic root of 20442239 is about 273.4278959283.

The spelling of 20442239 in words is "twenty million, four hundred forty-two thousand, two hundred thirty-nine".