131521431 has 4 divisors (see below), whose sum is σ = 175361912. Its totient is φ = 87680952.

The previous prime is 131521393. The next prime is 131521433. The reversal of 131521431 is 134125131.

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

It is not a de Polignac number, because 131521431 - 2¹⁷ = 131390359 is a prime.

It is a super-2 number, since 2×131521431² = 34595773624575522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131521398 and 131521407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131521433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21920236 + ... + 21920241.

It is an arithmetic number, because the mean of its divisors is an integer number (43840478).

Almost surely, 2^131521431 is an apocalyptic number.

131521431 is a deficient number, since it is larger than the sum of its proper divisors (43840481).

131521431 is an equidigital number, since it uses as much as digits as its factorization.

131521431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43840480.

The product of its digits is 360, while the sum is 21.

The square root of 131521431 is about 11468.2793391162. The cubic root of 131521431 is about 508.5482628763.

Adding to 131521431 its reverse (134125131), we get a palindrome (265646562).

The spelling of 131521431 in words is "one hundred thirty-one million, five hundred twenty-one thousand, four hundred thirty-one".