81139080888 has 40 divisors (see below), whose sum is σ = 227264557080. Its totient is φ = 27046360080.

The previous prime is 81139080823. The next prime is 81139080923. The reversal of 81139080888 is 88808093118.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 62606668 + ... + 62607963.

It is an arithmetic number, because the mean of its divisors is an integer number (5681613927).

Almost surely, 2^81139080888 is an apocalyptic number.

It is an amenable number.

81139080888 is an abundant number, since it is smaller than the sum of its proper divisors (146125476192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81139080888 is a wasteful number, since it uses less digits than its factorization.

81139080888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125214649 (or 125214636 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 54.

The spelling of 81139080888 in words is "eighty-one billion, one hundred thirty-nine million, eighty thousand, eight hundred eighty-eight".