20013239 has 2 divisors, whose sum is σ = 20013240. Its totient is φ = 20013238.

The previous prime is 20013223. The next prime is 20013241. The reversal of 20013239 is 93231002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20013239 - 2⁴ = 20013223 is a prime.

It is a super-2 number, since 2×20013239² = 801059470542242, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 20013241, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20013239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20013269) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006619 + 10006620.

It is an arithmetic number, because the mean of its divisors is an integer number (10006620).

Almost surely, 2^20013239 is an apocalyptic number.

20013239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20013239 is an equidigital number, since it uses as much as digits as its factorization.

20013239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 20013239 is about 4473.6158753295. The cubic root of 20013239 is about 271.5016420735.

The spelling of 20013239 in words is "twenty million, thirteen thousand, two hundred thirty-nine".