20131131239 has 2 divisors, whose sum is σ = 20131131240. Its totient is φ = 20131131238.

The previous prime is 20131131203. The next prime is 20131131253. The reversal of 20131131239 is 93213113102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20131131239 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20131131259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065565619 + 10065565620.

It is an arithmetic number, because the mean of its divisors is an integer number (10065565620).

Almost surely, 2^20131131239 is an apocalyptic number.

20131131239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131131239 is an equidigital number, since it uses as much as digits as its factorization.

20131131239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

The spelling of 20131131239 in words is "twenty billion, one hundred thirty-one million, one hundred thirty-one thousand, two hundred thirty-nine".