818185881 has 4 divisors (see below), whose sum is σ = 1090914512. Its totient is φ = 545457252.

The previous prime is 818185859. The next prime is 818185891. The reversal of 818185881 is 188581818.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 818185881 - 2⁶ = 818185817 is a prime.

It is a super-3 number, since 3×818185881³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 818185881.

It is not an unprimeable number, because it can be changed into a prime (818185891) 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, 136364311 + ... + 136364316.

It is an arithmetic number, because the mean of its divisors is an integer number (272728628).

Almost surely, 2^818185881 is an apocalyptic number.

It is an amenable number.

818185881 is a deficient number, since it is larger than the sum of its proper divisors (272728631).

818185881 is a wasteful number, since it uses less digits than its factorization.

818185881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272728630.

The product of its digits is 163840, while the sum is 48.

The square root of 818185881 is about 28603.9486959406. The cubic root of 818185881 is about 935.2994097689.

The spelling of 818185881 in words is "eight hundred eighteen million, one hundred eighty-five thousand, eight hundred eighty-one".