81858167178 has 32 divisors (see below), whose sum is σ = 169195955712. Its totient is φ = 26374852800.

The previous prime is 81858167137. The next prime is 81858167179. The reversal of 81858167178 is 87176185818.

It is not an unprimeable number, because it can be changed into a prime (81858167179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99313 + ... + 416628.

It is an arithmetic number, because the mean of its divisors is an integer number (5287373616).

Almost surely, 2^81858167178 is an apocalyptic number.

81858167178 is an abundant number, since it is smaller than the sum of its proper divisors (87337788534).

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

81858167178 is a wasteful number, since it uses less digits than its factorization.

81858167178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516830.

The product of its digits is 6021120, while the sum is 60.

The spelling of 81858167178 in words is "eighty-one billion, eight hundred fifty-eight million, one hundred sixty-seven thousand, one hundred seventy-eight".