81188466072 has 64 divisors (see below), whose sum is σ = 232272230400. Its totient is φ = 23166186240.

The previous prime is 81188466053. The next prime is 81188466089. The reversal of 81188466072 is 27066488118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 189672 + ... + 445367.

It is an arithmetic number, because the mean of its divisors is an integer number (3629253600).

Almost surely, 2^81188466072 is an apocalyptic number.

It is an amenable number.

81188466072 is an abundant number, since it is smaller than the sum of its proper divisors (151083764328).

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

81188466072 is a wasteful number, since it uses less digits than its factorization.

81188466072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635816 (or 635812 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 51.

The spelling of 81188466072 in words is "eighty-one billion, one hundred eighty-eight million, four hundred sixty-six thousand, seventy-two".