131551993 has 2 divisors, whose sum is σ = 131551994. Its totient is φ = 131551992.

The previous prime is 131551969. The next prime is 131551999. The reversal of 131551993 is 399155131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124724224 + 6827769 = 11168^2 + 2613^2 .

It is a cyclic number.

It is not a de Polignac number, because 131551993 - 2²⁵ = 97997561 is a prime.

It is not a weakly prime, because it can be changed into another prime (131551999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65775996 + 65775997.

It is an arithmetic number, because the mean of its divisors is an integer number (65775997).

Almost surely, 2^131551993 is an apocalyptic number.

It is an amenable number.

131551993 is a deficient number, since it is larger than the sum of its proper divisors (1).

131551993 is an equidigital number, since it uses as much as digits as its factorization.

131551993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18225, while the sum is 37.

The square root of 131551993 is about 11469.6117196704. The cubic root of 131551993 is about 508.5876507494.

The spelling of 131551993 in words is "one hundred thirty-one million, five hundred fifty-one thousand, nine hundred ninety-three".