81156081894 has 8 divisors (see below), whose sum is σ = 162312163800. Its totient is φ = 27052027296.

The previous prime is 81156081869. The next prime is 81156081943. The reversal of 81156081894 is 49818065118.

It is a sphenic number, since it is the product of 3 distinct primes.

81156081894 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6763006819 + ... + 6763006830.

It is an arithmetic number, because the mean of its divisors is an integer number (20289020475).

Almost surely, 2^81156081894 is an apocalyptic number.

81156081894 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81156081894 is a wasteful number, since it uses less digits than its factorization.

81156081894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13526013654.

The product of its (nonzero) digits is 552960, while the sum is 51.

The spelling of 81156081894 in words is "eighty-one billion, one hundred fifty-six million, eighty-one thousand, eight hundred ninety-four".