81362218861 has 16 divisors (see below), whose sum is σ = 101444866560. Its totient is φ = 63395221680.

The previous prime is 81362218859. The next prime is 81362218901. The reversal of 81362218861 is 16881226318.

It is not a de Polignac number, because 81362218861 - 2¹ = 81362218859 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 (81362218061) 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, 2319310 + ... + 2354128.

It is an arithmetic number, because the mean of its divisors is an integer number (6340304160).

Almost surely, 2^81362218861 is an apocalyptic number.

It is an amenable number.

81362218861 is a deficient number, since it is larger than the sum of its proper divisors (20082647699).

81362218861 is a wasteful number, since it uses less digits than its factorization.

81362218861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65184.

The product of its digits is 221184, while the sum is 46.

The spelling of 81362218861 in words is "eighty-one billion, three hundred sixty-two million, two hundred eighteen thousand, eight hundred sixty-one".