809499918 has 16 divisors (see below), whose sum is σ = 1620899280. Its totient is φ = 269516736.

The previous prime is 809499917. The next prime is 809499919. The reversal of 809499918 is 819994908.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (809499917) and next prime (809499919).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809499917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73573 + ... + 83856.

It is an arithmetic number, because the mean of its divisors is an integer number (101306205).

Almost surely, 2^809499918 is an apocalyptic number.

809499918 is an abundant number, since it is smaller than the sum of its proper divisors (811399362).

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

809499918 is a wasteful number, since it uses less digits than its factorization.

809499918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158291.

The product of its (nonzero) digits is 1679616, while the sum is 57.

The square root of 809499918 is about 28451.7120398756. The cubic root of 809499918 is about 931.9778763621.

The spelling of 809499918 in words is "eight hundred nine million, four hundred ninety-nine thousand, nine hundred eighteen".