131339981 has 2 divisors, whose sum is σ = 131339982. Its totient is φ = 131339980.

The previous prime is 131339969. The next prime is 131339983. The reversal of 131339981 is 189933131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117397225 + 13942756 = 10835^2 + 3734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131339981 is a prime.

It is a super-2 number, since 2×131339981² = 34500381218160722, which contains 22 as substring.

Together with 131339983, 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 (131339983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65669990 + 65669991.

It is an arithmetic number, because the mean of its divisors is an integer number (65669991).

Almost surely, 2^131339981 is an apocalyptic number.

It is an amenable number.

131339981 is a deficient number, since it is larger than the sum of its proper divisors (1).

131339981 is an equidigital number, since it uses as much as digits as its factorization.

131339981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17496, while the sum is 38.

The square root of 131339981 is about 11460.3656573427. The cubic root of 131339981 is about 508.3142869390.

It can be divided in two parts, 13 and 1339981, that multiplied together give a triangular number (17419753 = T₅₉₀₂).

The spelling of 131339981 in words is "one hundred thirty-one million, three hundred thirty-nine thousand, nine hundred eighty-one".