131561431 has 4 divisors (see below), whose sum is σ = 132349392. Its totient is φ = 130773472.

The previous prime is 131561407. The next prime is 131561501. The reversal of 131561431 is 134165131.

131561431 is nontrivially palindromic in base 16.

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-131561431 is a prime.

It is a super-2 number, since 2×131561431² = 34616820253535522, 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 = 131561396 and 131561405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131561531) 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, 393730 + ... + 394063.

It is an arithmetic number, because the mean of its divisors is an integer number (33087348).

Almost surely, 2^131561431 is an apocalyptic number.

131561431 is a deficient number, since it is larger than the sum of its proper divisors (787961).

131561431 is an equidigital number, since it uses as much as digits as its factorization.

131561431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787960.

The product of its digits is 1080, while the sum is 25.

The square root of 131561431 is about 11470.0231473175. The cubic root of 131561431 is about 508.5998130774.

The spelling of 131561431 in words is "one hundred thirty-one million, five hundred sixty-one thousand, four hundred thirty-one".