20823239 has 2 divisors, whose sum is σ = 20823240. Its totient is φ = 20823238.

The previous prime is 20823169. The next prime is 20823263. The reversal of 20823239 is 93232802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20823239 - 2¹² = 20819143 is a prime.

It is a super-2 number, since 2×20823239² = 867214564902242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20823269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10411619 + 10411620.

It is an arithmetic number, because the mean of its divisors is an integer number (10411620).

Almost surely, 2^20823239 is an apocalyptic number.

20823239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20823239 is an equidigital number, since it uses as much as digits as its factorization.

20823239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20823239 is about 4563.2487330848. The cubic root of 20823239 is about 275.1161558893.

The spelling of 20823239 in words is "twenty million, eight hundred twenty-three thousand, two hundred thirty-nine".