81800119 has 2 divisors, whose sum is σ = 81800120. Its totient is φ = 81800118.

The previous prime is 81800093. The next prime is 81800221. The reversal of 81800119 is 91100818.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81800119 is a prime.

It is a super-3 number, since 3×81800119³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81800519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40900059 + 40900060.

It is an arithmetic number, because the mean of its divisors is an integer number (40900060).

Almost surely, 2^81800119 is an apocalyptic number.

81800119 is a deficient number, since it is larger than the sum of its proper divisors (1).

81800119 is an equidigital number, since it uses as much as digits as its factorization.

81800119 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 81800119 is about 9044.3418223771. The cubic root of 81800119 is about 434.0948616499.

The spelling of 81800119 in words is "eighty-one million, eight hundred thousand, one hundred nineteen".