18117320 has 32 divisors (see below), whose sum is σ = 43900920. Its totient is φ = 6689280.

The previous prime is 18117313. The next prime is 18117331. The reversal of 18117320 is 2371181.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7761796 + 10355524 = 2786^2 + 3218^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16901 + ... + 17940.

Almost surely, 2^18117320 is an apocalyptic number.

18117320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18117320 is an abundant number, since it is smaller than the sum of its proper divisors (25783600).

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

18117320 is a wasteful number, since it uses less digits than its factorization.

18117320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34865 (or 34861 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 18117320 is about 4256.4445256575. Note that the first 3 decimals coincide. The cubic root of 18117320 is about 262.6422871833.

The spelling of 18117320 in words is "eighteen million, one hundred seventeen thousand, three hundred twenty".