20113131 has 4 divisors (see below), whose sum is σ = 26817512. Its totient is φ = 13408752.

The previous prime is 20113127. The next prime is 20113139. The reversal of 20113131 is 13131102.

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

It is not a de Polignac number, because 20113131 - 2² = 20113127 is a prime.

It is a super-2 number, since 2×20113131² = 809076077246322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20113139) 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, 3352186 + ... + 3352191.

It is an arithmetic number, because the mean of its divisors is an integer number (6704378).

Almost surely, 2^20113131 is an apocalyptic number.

20113131 is a deficient number, since it is larger than the sum of its proper divisors (6704381).

20113131 is an equidigital number, since it uses as much as digits as its factorization.

20113131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6704380.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 20113131 is about 4484.7665491082. The cubic root of 20113131 is about 271.9526076239.

Adding to 20113131 its reverse (13131102), we get a palindrome (33244233).

The spelling of 20113131 in words is "twenty million, one hundred thirteen thousand, one hundred thirty-one".