81389183 has 4 divisors (see below), whose sum is σ = 86176800. Its totient is φ = 76601568.

The previous prime is 81389177. The next prime is 81389201. The reversal of 81389183 is 38198318.

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 81389183 - 2¹⁶ = 81323647 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81389183.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81389123) 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, 2393783 + ... + 2393816.

It is an arithmetic number, because the mean of its divisors is an integer number (21544200).

Almost surely, 2^81389183 is an apocalyptic number.

81389183 is a deficient number, since it is larger than the sum of its proper divisors (4787617).

81389183 is a wasteful number, since it uses less digits than its factorization.

81389183 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4787616.

The product of its digits is 41472, while the sum is 41.

The square root of 81389183 is about 9021.5953688912. The cubic root of 81389183 is about 433.3667259606.

The spelling of 81389183 in words is "eighty-one million, three hundred eighty-nine thousand, one hundred eighty-three".