20228239 has 2 divisors, whose sum is σ = 20228240. Its totient is φ = 20228238.

The previous prime is 20228207. The next prime is 20228267. The reversal of 20228239 is 93282202.

It is an a-pointer prime, because the next prime (20228267) can be obtained adding 20228239 to its sum of digits (28).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20228239 - 2⁵ = 20228207 is a prime.

It is a super-2 number, since 2×20228239² = 818363306082242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20228269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10114119 + 10114120.

It is an arithmetic number, because the mean of its divisors is an integer number (10114120).

Almost surely, 2^20228239 is an apocalyptic number.

20228239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20228239 is an equidigital number, since it uses as much as digits as its factorization.

20228239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20228239 is about 4497.5814611856. The cubic root of 20228239 is about 272.4704184705.

It can be divided in two parts, 202 and 28239, that added together give a triangular number (28441 = T₂₃₈).

The spelling of 20228239 in words is "twenty million, two hundred twenty-eight thousand, two hundred thirty-nine".