20365139 has 2 divisors, whose sum is σ = 20365140. Its totient is φ = 20365138.

The previous prime is 20365127. The next prime is 20365141. The reversal of 20365139 is 93156302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20365139 - 2⁴ = 20365123 is a prime.

It is a Sophie Germain prime.

Together with 20365141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20365039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10182569 + 10182570.

It is an arithmetic number, because the mean of its divisors is an integer number (10182570).

Almost surely, 2^20365139 is an apocalyptic number.

20365139 is a deficient number, since it is larger than the sum of its proper divisors (1).

20365139 is an equidigital number, since it uses as much as digits as its factorization.

20365139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 20365139 is about 4512.7750885680. The cubic root of 20365139 is about 273.0837090730.

The spelling of 20365139 in words is "twenty million, three hundred sixty-five thousand, one hundred thirty-nine".