131819999 has 2 divisors, whose sum is σ = 131820000. Its totient is φ = 131819998.

The previous prime is 131819981. The next prime is 131820001. The reversal of 131819999 is 999918131.

It is a strong prime.

It is an emirp because it is prime and its reverse (999918131) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131819999 is a prime.

Together with 131820001, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131819899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65909999 + 65910000.

It is an arithmetic number, because the mean of its divisors is an integer number (65910000).

Almost surely, 2^131819999 is an apocalyptic number.

131819999 is a deficient number, since it is larger than the sum of its proper divisors (1).

131819999 is an equidigital number, since it uses as much as digits as its factorization.

131819999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 50.

The square root of 131819999 is about 11481.2890826771. The cubic root of 131819999 is about 508.9327920650.

The spelling of 131819999 in words is "one hundred thirty-one million, eight hundred nineteen thousand, nine hundred ninety-nine".