819909918 has 16 divisors (see below), whose sum is σ = 1822022160. Its totient is φ = 273303288.

The previous prime is 819909913. The next prime is 819909941.

819909918 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 15183517 = 819909918 / (8 + 1 + 9 + 9 + 0 + 9 + 9 + 1 + 8).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819909913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7591705 + ... + 7591812.

It is an arithmetic number, because the mean of its divisors is an integer number (113876385).

Almost surely, 2^819909918 is an apocalyptic number.

819909918 is an abundant number, since it is smaller than the sum of its proper divisors (1002112242).

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

819909918 is a wasteful number, since it uses less digits than its factorization.

819909918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15183528 (or 15183522 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 54.

The square root of 819909918 is about 28634.0691834046. The cubic root of 819909918 is about 935.9558863167.

The spelling of 819909918 in words is "eight hundred nineteen million, nine hundred nine thousand, nine hundred eighteen".