81231461099 has 2 divisors, whose sum is σ = 81231461100. Its totient is φ = 81231461098.

The previous prime is 81231461057. The next prime is 81231461107. The reversal of 81231461099 is 99016413218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81231461099 - 2²⁴ = 81214683883 is a prime.

It is not a weakly prime, because it can be changed into another prime (81231461009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40615730549 + 40615730550.

It is an arithmetic number, because the mean of its divisors is an integer number (40615730550).

Almost surely, 2^81231461099 is an apocalyptic number.

81231461099 is a deficient number, since it is larger than the sum of its proper divisors (1).

81231461099 is an equidigital number, since it uses as much as digits as its factorization.

81231461099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The spelling of 81231461099 in words is "eighty-one billion, two hundred thirty-one million, four hundred sixty-one thousand, ninety-nine".