819989918 has 32 divisors (see below), whose sum is σ = 1376732160. Its totient is φ = 363094560.

The previous prime is 819989909. The next prime is 819989927.

819989918 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (819989909) and next prime (819989927).

It is a congruent number.

It is an unprimeable number.

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, 235055 + ... + 238517.

It is an arithmetic number, because the mean of its divisors is an integer number (43022880).

Almost surely, 2^819989918 is an apocalyptic number.

819989918 is a deficient number, since it is larger than the sum of its proper divisors (556742242).

819989918 is a wasteful number, since it uses less digits than its factorization.

819989918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3752.

The product of its digits is 3359232, while the sum is 62.

The square root of 819989918 is about 28635.4660866555. The cubic root of 819989918 is about 935.9863262607.

The spelling of 819989918 in words is "eight hundred nineteen million, nine hundred eighty-nine thousand, nine hundred eighteen".