81522872587 has 8 divisors (see below), whose sum is σ = 87796082304. Its totient is φ = 75249979968.

The previous prime is 81522872539. The next prime is 81522872603. The reversal of 81522872587 is 78527822518.

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 81522872587 - 2²⁷ = 81388654859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81522872507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 943263 + ... + 1026055.

It is an arithmetic number, because the mean of its divisors is an integer number (10974510288).

Almost surely, 2^81522872587 is an apocalyptic number.

81522872587 is a deficient number, since it is larger than the sum of its proper divisors (6273209717).

81522872587 is a wasteful number, since it uses less digits than its factorization.

81522872587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158549.

The product of its digits is 5017600, while the sum is 55.

The spelling of 81522872587 in words is "eighty-one billion, five hundred twenty-two million, eight hundred seventy-two thousand, five hundred eighty-seven".