81254542430899 has 2 divisors, whose sum is σ = 81254542430900. Its totient is φ = 81254542430898.

The previous prime is 81254542430849. The next prime is 81254542430951. The reversal of 81254542430899 is 99803424545218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81254542430899 - 2²⁵ = 81254508876467 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81254542430899.

It is not a weakly prime, because it can be changed into another prime (81254542430849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40627271215449 + 40627271215450.

It is an arithmetic number, because the mean of its divisors is an integer number (40627271215450).

Almost surely, 2^{81254542430899} is an apocalyptic number.

81254542430899 is a deficient number, since it is larger than the sum of its proper divisors (1).

81254542430899 is an equidigital number, since it uses as much as digits as its factorization.

81254542430899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 99532800, while the sum is 64.

The spelling of 81254542430899 in words is "eighty-one trillion, two hundred fifty-four billion, five hundred forty-two million, four hundred thirty thousand, eight hundred ninety-nine".