81098870819 has 2 divisors, whose sum is σ = 81098870820. Its totient is φ = 81098870818.

The previous prime is 81098870771. The next prime is 81098870833. The reversal of 81098870819 is 91807889018.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81098870819 - 2²⁰ = 81097822243 is a prime.

It is a super-2 number, since 2×81098870819² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81098870119) 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, 40549435409 + 40549435410.

It is an arithmetic number, because the mean of its divisors is an integer number (40549435410).

Almost surely, 2^81098870819 is an apocalyptic number.

81098870819 is a deficient number, since it is larger than the sum of its proper divisors (1).

81098870819 is an equidigital number, since it uses as much as digits as its factorization.

81098870819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2322432, while the sum is 59.

The spelling of 81098870819 in words is "eighty-one billion, ninety-eight million, eight hundred seventy thousand, eight hundred nineteen".