81287580361 has 16 divisors (see below), whose sum is σ = 87986868480. Its totient is φ = 74652641280.

The previous prime is 81287580337. The next prime is 81287580379. The reversal of 81287580361 is 16308578218.

It is a cyclic number.

It is not a de Polignac number, because 81287580361 - 2¹⁹ = 81287056073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81287580461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3571026 + ... + 3593716.

It is an arithmetic number, because the mean of its divisors is an integer number (5499179280).

Almost surely, 2^81287580361 is an apocalyptic number.

It is an amenable number.

81287580361 is a deficient number, since it is larger than the sum of its proper divisors (6699288119).

81287580361 is a wasteful number, since it uses less digits than its factorization.

81287580361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24096.

The product of its (nonzero) digits is 645120, while the sum is 49.

The spelling of 81287580361 in words is "eighty-one billion, two hundred eighty-seven million, five hundred eighty thousand, three hundred sixty-one".