131681345 has 4 divisors (see below), whose sum is σ = 158017620. Its totient is φ = 105345072.

The previous prime is 131681311. The next prime is 131681383. The reversal of 131681345 is 543186131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 543186131 = 109 ⋅4983359.

It can be written as a sum of positive squares in 2 ways, for example, as 88134544 + 43546801 = 9388^2 + 6599^2 .

It is a cyclic number.

It is not a de Polignac number, because 131681345 - 2⁶ = 131681281 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13168130 + ... + 13168139.

It is an arithmetic number, because the mean of its divisors is an integer number (39504405).

Almost surely, 2^131681345 is an apocalyptic number.

It is an amenable number.

131681345 is a deficient number, since it is larger than the sum of its proper divisors (26336275).

131681345 is an equidigital number, since it uses as much as digits as its factorization.

131681345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26336274.

The product of its digits is 8640, while the sum is 32.

The square root of 131681345 is about 11475.2492347661. The cubic root of 131681345 is about 508.7542902604.

The spelling of 131681345 in words is "one hundred thirty-one million, six hundred eighty-one thousand, three hundred forty-five".