81272618587 has 4 divisors (see below), whose sum is σ = 81790278736. Its totient is φ = 80754958440.

The previous prime is 81272618561. The next prime is 81272618621. The reversal of 81272618587 is 78581627218.

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 81272618587 - 2¹¹ = 81272616539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81272612587) 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, 258829839 + ... + 258830152.

It is an arithmetic number, because the mean of its divisors is an integer number (20447569684).

Almost surely, 2^81272618587 is an apocalyptic number.

81272618587 is a deficient number, since it is larger than the sum of its proper divisors (517660149).

81272618587 is a wasteful number, since it uses less digits than its factorization.

81272618587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517660148.

The product of its digits is 3010560, while the sum is 55.

The spelling of 81272618587 in words is "eighty-one billion, two hundred seventy-two million, six hundred eighteen thousand, five hundred eighty-seven".