81581341108 has 6 divisors (see below), whose sum is σ = 142767346946. Its totient is φ = 40790670552.

The previous prime is 81581341091. The next prime is 81581341133. The reversal of 81581341108 is 80114318518.

It can be written as a sum of positive squares in only one way, i.e., 81406361124 + 174979984 = 285318^2 + 13228^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10197667635 + ... + 10197667642.

Almost surely, 2^81581341108 is an apocalyptic number.

It is an amenable number.

81581341108 is a deficient number, since it is larger than the sum of its proper divisors (61186005838).

81581341108 is a wasteful number, since it uses less digits than its factorization.

81581341108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20395335281 (or 20395335279 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 40.

The spelling of 81581341108 in words is "eighty-one billion, five hundred eighty-one million, three hundred forty-one thousand, one hundred eight".