18722113 has 2 divisors, whose sum is σ = 18722114. Its totient is φ = 18722112.

The previous prime is 18722107. The next prime is 18722149. The reversal of 18722113 is 31122781.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16507969 + 2214144 = 4063^2 + 1488^2 .

It is a cyclic number.

It is not a de Polignac number, because 18722113 - 2⁹ = 18721601 is a prime.

It is not a weakly prime, because it can be changed into another prime (18722173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9361056 + 9361057.

It is an arithmetic number, because the mean of its divisors is an integer number (9361057).

Almost surely, 2^18722113 is an apocalyptic number.

It is an amenable number.

18722113 is a deficient number, since it is larger than the sum of its proper divisors (1).

18722113 is an equidigital number, since it uses as much as digits as its factorization.

18722113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 25.

The square root of 18722113 is about 4326.9057073156. The cubic root of 18722113 is about 265.5328686803.

Adding to 18722113 its reverse (31122781), we get a palindrome (49844894).

The spelling of 18722113 in words is "eighteen million, seven hundred twenty-two thousand, one hundred thirteen".