131609993 has 2 divisors, whose sum is σ = 131609994. Its totient is φ = 131609992.

The previous prime is 131609983. The next prime is 131610007. The reversal of 131609993 is 399906131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69089344 + 62520649 = 8312^2 + 7907^2 .

It is a cyclic number.

It is not a de Polignac number, because 131609993 - 2⁴ = 131609977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 131609993.

It is not a weakly prime, because it can be changed into another prime (131609953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65804996 + 65804997.

It is an arithmetic number, because the mean of its divisors is an integer number (65804997).

Almost surely, 2^131609993 is an apocalyptic number.

It is an amenable number.

131609993 is a deficient number, since it is larger than the sum of its proper divisors (1).

131609993 is an equidigital number, since it uses as much as digits as its factorization.

131609993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 131609993 is about 11472.1398614208. The cubic root of 131609993 is about 508.6623835578.

The spelling of 131609993 in words is "one hundred thirty-one million, six hundred nine thousand, nine hundred ninety-three".