81268180312078 has 4 divisors (see below), whose sum is σ = 121902270468120. Its totient is φ = 40634090156038.

The previous prime is 81268180312061. The next prime is 81268180312091. The reversal of 81268180312078 is 87021308186218.

It is a semiprime because it is the product of two primes.

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, 20317045078018 + ... + 20317045078021.

It is an arithmetic number, because the mean of its divisors is an integer number (30475567617030).

Almost surely, 2^{81268180312078} is an apocalyptic number.

81268180312078 is a deficient number, since it is larger than the sum of its proper divisors (40634090156042).

81268180312078 is a wasteful number, since it uses less digits than its factorization.

81268180312078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40634090156041.

The product of its (nonzero) digits is 2064384, while the sum is 55.

The spelling of 81268180312078 in words is "eighty-one trillion, two hundred sixty-eight billion, one hundred eighty million, three hundred twelve thousand, seventy-eight".