81888818 has 8 divisors (see below), whose sum is σ = 133999920. Its totient is φ = 37222180.

The previous prime is 81888787. The next prime is 81888827.

It is a happy number.

81888818 is nontrivially palindromic in base 10.

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

81888818 is a strobogrammatic number because it is the same when read upside-down.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1861088 + ... + 1861131.

It is an arithmetic number, because the mean of its divisors is an integer number (16749990).

Almost surely, 2^81888818 is an apocalyptic number.

81888818 is a deficient number, since it is larger than the sum of its proper divisors (52111102).

81888818 is a wasteful number, since it uses less digits than its factorization.

81888818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3722232.

The product of its digits is 262144, while the sum is 50.

The square root of 81888818 is about 9049.2440568260. The cubic root of 81888818 is about 434.2517068638.

The spelling of 81888818 in words is "eighty-one million, eight hundred eighty-eight thousand, eight hundred eighteen".