20131120031 has 4 divisors (see below), whose sum is σ = 21961221864. Its totient is φ = 18301018200.

The previous prime is 20131120019. The next prime is 20131120049. The reversal of 20131120031 is 13002113102.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20131120031 is a prime.

It is a super-2 number, since 2×20131120031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20131119988 and 20131120015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131120931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 915050900 + ... + 915050921.

It is an arithmetic number, because the mean of its divisors is an integer number (5490305466).

Almost surely, 2^20131120031 is an apocalyptic number.

20131120031 is a deficient number, since it is larger than the sum of its proper divisors (1830101833).

20131120031 is a wasteful number, since it uses less digits than its factorization.

20131120031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1830101832.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 20131120031 its reverse (13002113102), we get a palindrome (33133233133).

The spelling of 20131120031 in words is "twenty billion, one hundred thirty-one million, one hundred twenty thousand, thirty-one".