81255559 has 8 divisors (see below), whose sum is σ = 101305728. Its totient is φ = 63315960.

The previous prime is 81255547. The next prime is 81255583. The reversal of 81255559 is 95555218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81255559 - 2⁷ = 81255431 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 (81255539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 527557 + ... + 527710.

It is an arithmetic number, because the mean of its divisors is an integer number (12663216).

Almost surely, 2^81255559 is an apocalyptic number.

81255559 is a deficient number, since it is larger than the sum of its proper divisors (20050169).

81255559 is a wasteful number, since it uses less digits than its factorization.

81255559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1055285.

The product of its digits is 90000, while the sum is 40.

The square root of 81255559 is about 9014.1865412249. The cubic root of 81255559 is about 433.1294302363.

The spelling of 81255559 in words is "eighty-one million, two hundred fifty-five thousand, five hundred fifty-nine".