131819861 has 2 divisors, whose sum is σ = 131819862. Its totient is φ = 131819860.

The previous prime is 131819803. The next prime is 131819873. The reversal of 131819861 is 168918131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118679236 + 13140625 = 10894^2 + 3625^2 .

It is a cyclic number.

It is not a de Polignac number, because 131819861 - 2²² = 127625557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131819881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65909930 + 65909931.

It is an arithmetic number, because the mean of its divisors is an integer number (65909931).

Almost surely, 2^131819861 is an apocalyptic number.

It is an amenable number.

131819861 is a deficient number, since it is larger than the sum of its proper divisors (1).

131819861 is an equidigital number, since it uses as much as digits as its factorization.

131819861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 38.

The square root of 131819861 is about 11481.2830728974. The cubic root of 131819861 is about 508.9326144674.

The spelling of 131819861 in words is "one hundred thirty-one million, eight hundred nineteen thousand, eight hundred sixty-one".