81387278318 has 8 divisors (see below), whose sum is σ = 122082219480. Its totient is φ = 40693205160.

The previous prime is 81387278173. The next prime is 81387278341.

81387278318 is nontrivially palindromic in base 10.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125573 + ... + 422543.

It is an arithmetic number, because the mean of its divisors is an integer number (15260277435).

Almost surely, 2^81387278318 is an apocalyptic number.

81387278318 is a deficient number, since it is larger than the sum of its proper divisors (40694941162).

81387278318 is a wasteful number, since it uses less digits than its factorization.

81387278318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434002.

The product of its digits is 3612672, while the sum is 56.

The spelling of 81387278318 in words is "eighty-one billion, three hundred eighty-seven million, two hundred seventy-eight thousand, three hundred eighteen".