81427998167 has 4 divisors (see below), whose sum is σ = 82218561360. Its totient is φ = 80637434976.

The previous prime is 81427998149. The next prime is 81427998191. The reversal of 81427998167 is 76189972418.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81427998167 - 2¹⁰ = 81427997143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81427998367) by changing a digit.

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, 395281442 + ... + 395281647.

It is an arithmetic number, because the mean of its divisors is an integer number (20554640340).

Almost surely, 2^81427998167 is an apocalyptic number.

81427998167 is a deficient number, since it is larger than the sum of its proper divisors (790563193).

81427998167 is a wasteful number, since it uses less digits than its factorization.

81427998167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790563192.

The product of its digits is 12192768, while the sum is 62.

The spelling of 81427998167 in words is "eighty-one billion, four hundred twenty-seven million, nine hundred ninety-eight thousand, one hundred sixty-seven".