20131132531 has 4 divisors (see below), whose sum is σ = 20675217232. Its totient is φ = 19587047832.

The previous prime is 20131132523. The next prime is 20131132561. The reversal of 20131132531 is 13523113102.

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

It is a cyclic number.

It is not a de Polignac number, because 20131132531 - 2³ = 20131132523 is a prime.

It is a super-2 number, since 2×20131132531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20131132561) 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, 272042295 + ... + 272042368.

It is an arithmetic number, because the mean of its divisors is an integer number (5168804308).

Almost surely, 2^20131132531 is an apocalyptic number.

20131132531 is a deficient number, since it is larger than the sum of its proper divisors (544084701).

20131132531 is an equidigital number, since it uses as much as digits as its factorization.

20131132531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544084700.

The product of its (nonzero) digits is 540, while the sum is 22.

Adding to 20131132531 its reverse (13523113102), we get a palindrome (33654245633).

The spelling of 20131132531 in words is "twenty billion, one hundred thirty-one million, one hundred thirty-two thousand, five hundred thirty-one".