131297981 has 2 divisors, whose sum is σ = 131297982. Its totient is φ = 131297980.

The previous prime is 131297917. The next prime is 131297983. The reversal of 131297981 is 189792131.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130759225 + 538756 = 11435^2 + 734^2 .

It is a cyclic number.

It is not a de Polignac number, because 131297981 - 2⁶ = 131297917 is a prime.

It is a super-2 number, since 2×131297981² = 34478319629352722, which contains 22 as substring.

Together with 131297983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131297983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65648990 + 65648991.

It is an arithmetic number, because the mean of its divisors is an integer number (65648991).

Almost surely, 2^131297981 is an apocalyptic number.

It is an amenable number.

131297981 is a deficient number, since it is larger than the sum of its proper divisors (1).

131297981 is an equidigital number, since it uses as much as digits as its factorization.

131297981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 41.

The square root of 131297981 is about 11458.5331085615. The cubic root of 131297981 is about 508.2600981181.

The spelling of 131297981 in words is "one hundred thirty-one million, two hundred ninety-seven thousand, nine hundred eighty-one".