18220117 has 4 divisors (see below), whose sum is σ = 19012320. Its totient is φ = 17427916.

The previous prime is 18220109. The next prime is 18220121. The reversal of 18220117 is 71102281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71102281 = 479 ⋅148439.

It is a cyclic number.

It is not a de Polignac number, because 18220117 - 2³ = 18220109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18220127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396067 + ... + 396112.

It is an arithmetic number, because the mean of its divisors is an integer number (4753080).

Almost surely, 2^18220117 is an apocalyptic number.

It is an amenable number.

18220117 is a deficient number, since it is larger than the sum of its proper divisors (792203).

18220117 is an equidigital number, since it uses as much as digits as its factorization.

18220117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792202.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 18220117 is about 4268.5028991439. The cubic root of 18220117 is about 263.1380914944.

Adding to 18220117 its reverse (71102281), we get a palindrome (89322398).

The spelling of 18220117 in words is "eighteen million, two hundred twenty thousand, one hundred seventeen".