81417559 has 4 divisors (see below), whose sum is σ = 81444160. Its totient is φ = 81390960.

The previous prime is 81417547. The next prime is 81417569. The reversal of 81417559 is 95571418.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81417559 - 2¹¹ = 81415511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81417509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8007 + ... + 15064.

It is an arithmetic number, because the mean of its divisors is an integer number (20361040).

Almost surely, 2^81417559 is an apocalyptic number.

81417559 is a deficient number, since it is larger than the sum of its proper divisors (26601).

81417559 is a wasteful number, since it uses less digits than its factorization.

81417559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26600.

The product of its digits is 50400, while the sum is 40.

The square root of 81417559 is about 9023.1679026825. The cubic root of 81417559 is about 433.4170839439.

The spelling of 81417559 in words is "eighty-one million, four hundred seventeen thousand, five hundred fifty-nine".