131666531 has 2 divisors, whose sum is σ = 131666532. Its totient is φ = 131666530.

The previous prime is 131666519. The next prime is 131666533. The reversal of 131666531 is 135666131.

It is a strong prime.

It is an emirp because it is prime and its reverse (135666131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131666531 - 2²² = 127472227 is a prime.

It is a super-2 number, since 2×131666531² = 34672150771147922, which contains 22 as substring.

Together with 131666533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (131666533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65833265 + 65833266.

It is an arithmetic number, because the mean of its divisors is an integer number (65833266).

Almost surely, 2^131666531 is an apocalyptic number.

131666531 is a deficient number, since it is larger than the sum of its proper divisors (1).

131666531 is an equidigital number, since it uses as much as digits as its factorization.

131666531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 32.

The square root of 131666531 is about 11474.6037404348. The cubic root of 131666531 is about 508.7352114539.

The spelling of 131666531 in words is "one hundred thirty-one million, six hundred sixty-six thousand, five hundred thirty-one".