81986572587 has 8 divisors (see below), whose sum is σ = 109422711360. Its totient is φ = 54604074440.

The previous prime is 81986572583. The next prime is 81986572601. The reversal of 81986572587 is 78527568918.

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 81986572587 - 2² = 81986572583 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81986572583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13406589 + ... + 13412702.

It is an arithmetic number, because the mean of its divisors is an integer number (13677838920).

Almost surely, 2^81986572587 is an apocalyptic number.

81986572587 is a deficient number, since it is larger than the sum of its proper divisors (27436138773).

81986572587 is a wasteful number, since it uses less digits than its factorization.

81986572587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26820313.

The product of its digits is 67737600, while the sum is 66.

The spelling of 81986572587 in words is "eighty-one billion, nine hundred eighty-six million, five hundred seventy-two thousand, five hundred eighty-seven".