81140557867 has 4 divisors (see below), whose sum is σ = 81141238240. Its totient is φ = 81139877496.

The previous prime is 81140557837. The next prime is 81140557951. The reversal of 81140557867 is 76875504118.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 81140557867 - 2¹⁵ = 81140525099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81140557837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108867 + ... + 417292.

It is an arithmetic number, because the mean of its divisors is an integer number (20285309560).

Almost surely, 2^81140557867 is an apocalyptic number.

81140557867 is a deficient number, since it is larger than the sum of its proper divisors (680373).

81140557867 is a wasteful number, since it uses less digits than its factorization.

81140557867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680372.

The product of its (nonzero) digits is 1881600, while the sum is 52.

The spelling of 81140557867 in words is "eighty-one billion, one hundred forty million, five hundred fifty-seven thousand, eight hundred sixty-seven".