131516531 has 2 divisors, whose sum is σ = 131516532. Its totient is φ = 131516530.

The previous prime is 131516509. The next prime is 131516543. The reversal of 131516531 is 135615131.

It is a strong prime.

It is an emirp because it is prime and its reverse (135615131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131516531 - 2⁶ = 131516467 is a prime.

It is a super-2 number, since 2×131516531² = 34593195852547922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131516531.

It is not a weakly prime, because it can be changed into another prime (131516731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65758265 + 65758266.

It is an arithmetic number, because the mean of its divisors is an integer number (65758266).

Almost surely, 2^131516531 is an apocalyptic number.

131516531 is a deficient number, since it is larger than the sum of its proper divisors (1).

131516531 is an equidigital number, since it uses as much as digits as its factorization.

131516531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1350, while the sum is 26.

The square root of 131516531 is about 11468.0657043810. The cubic root of 131516531 is about 508.5419472581.

The spelling of 131516531 in words is "one hundred thirty-one million, five hundred sixteen thousand, five hundred thirty-one".