131693021 has 2 divisors, whose sum is σ = 131693022. Its totient is φ = 131693020.

The previous prime is 131693017. The next prime is 131693057. The reversal of 131693021 is 120396131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94848121 + 36844900 = 9739^2 + 6070^2 .

It is a cyclic number.

It is not a de Polignac number, because 131693021 - 2² = 131693017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131693011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65846510 + 65846511.

It is an arithmetic number, because the mean of its divisors is an integer number (65846511).

Almost surely, 2^131693021 is an apocalyptic number.

It is an amenable number.

131693021 is a deficient number, since it is larger than the sum of its proper divisors (1).

131693021 is an equidigital number, since it uses as much as digits as its factorization.

131693021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 131693021 is about 11475.7579706092. The cubic root of 131693021 is about 508.7693266589.

The spelling of 131693021 in words is "one hundred thirty-one million, six hundred ninety-three thousand, twenty-one".