81530711178 has 32 divisors (see below), whose sum is σ = 196164119040. Its totient is φ = 22068462960.

The previous prime is 81530711177. The next prime is 81530711183. The reversal of 81530711178 is 87111703518.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (81530711173) 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, 51083608 + ... + 51085203.

It is an arithmetic number, because the mean of its divisors is an integer number (6130128720).

Almost surely, 2^81530711178 is an apocalyptic number.

81530711178 is an abundant number, since it is smaller than the sum of its proper divisors (114633407862).

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

81530711178 is a wasteful number, since it uses less digits than its factorization.

81530711178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102168842.

The product of its (nonzero) digits is 47040, while the sum is 42.

The spelling of 81530711178 in words is "eighty-one billion, five hundred thirty million, seven hundred eleven thousand, one hundred seventy-eight".