20131131238 has 4 divisors (see below), whose sum is σ = 30196696860. Its totient is φ = 10065565618.

The previous prime is 20131131203. The next prime is 20131131239. The reversal of 20131131238 is 83213113102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131131239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5032782808 + ... + 5032782811.

It is an arithmetic number, because the mean of its divisors is an integer number (7549174215).

Almost surely, 2^20131131238 is an apocalyptic number.

20131131238 is a deficient number, since it is larger than the sum of its proper divisors (10065565622).

20131131238 is a wasteful number, since it uses less digits than its factorization.

20131131238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10065565621.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 20131131238 in words is "twenty billion, one hundred thirty-one million, one hundred thirty-one thousand, two hundred thirty-eight".