81854538 has 8 divisors (see below), whose sum is σ = 163709088. Its totient is φ = 27284844.

The previous prime is 81854537. The next prime is 81854599. The reversal of 81854538 is 83545818.

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

81854538 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 81854538.

It is not an unprimeable number, because it can be changed into a prime (81854537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6821206 + ... + 6821217.

It is an arithmetic number, because the mean of its divisors is an integer number (20463636).

Almost surely, 2^81854538 is an apocalyptic number.

81854538 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81854538 is a wasteful number, since it uses less digits than its factorization.

81854538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13642428.

The product of its digits is 153600, while the sum is 42.

The square root of 81854538 is about 9047.3497776973. The cubic root of 81854538 is about 434.1911034482.

The spelling of 81854538 in words is "eighty-one million, eight hundred fifty-four thousand, five hundred thirty-eight".