81102559 has 2 divisors, whose sum is σ = 81102560. Its totient is φ = 81102558.

The previous prime is 81102523. The next prime is 81102587. The reversal of 81102559 is 95520118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81102559 - 2¹³ = 81094367 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81102559.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81102599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40551279 + 40551280.

It is an arithmetic number, because the mean of its divisors is an integer number (40551280).

Almost surely, 2^81102559 is an apocalyptic number.

81102559 is a deficient number, since it is larger than the sum of its proper divisors (1).

81102559 is an equidigital number, since it uses as much as digits as its factorization.

81102559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 81102559 is about 9005.6959198054. The cubic root of 81102559 is about 432.8574060172.

The spelling of 81102559 in words is "eighty-one million, one hundred two thousand, five hundred fifty-nine".