131012561 has 4 divisors (see below), whose sum is σ = 131161152. Its totient is φ = 130863972.

The previous prime is 131012551. The next prime is 131012569. The reversal of 131012561 is 165210131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 131012561 - 2²² = 126818257 is a prime.

It is a super-2 number, since 2×131012561² = 34328582279557442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (131012569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72965 + ... + 74738.

It is an arithmetic number, because the mean of its divisors is an integer number (32790288).

Almost surely, 2^131012561 is an apocalyptic number.

It is an amenable number.

131012561 is a deficient number, since it is larger than the sum of its proper divisors (148591).

131012561 is an equidigital number, since it uses as much as digits as its factorization.

131012561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148590.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 131012561 is about 11446.0718589392. The cubic root of 131012561 is about 507.8915399198.

Adding to 131012561 its reverse (165210131), we get a palindrome (296222692).

The spelling of 131012561 in words is "one hundred thirty-one million, twelve thousand, five hundred sixty-one".