18985121 has 4 divisors (see below), whose sum is σ = 19008132. Its totient is φ = 18962112.

The previous prime is 18985093. The next prime is 18985157. The reversal of 18985121 is 12158981.

18985121 = 55⁴ + 56⁴.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12158981 = 43 ⋅282767.

It can be written as a sum of positive squares in 2 ways, for example, as 9150625 + 9834496 = 3025^2 + 3136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18985121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18985721) 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, 10220 + ... + 11933.

It is an arithmetic number, because the mean of its divisors is an integer number (4752033).

Almost surely, 2^18985121 is an apocalyptic number.

It is an amenable number.

18985121 is a deficient number, since it is larger than the sum of its proper divisors (23011).

18985121 is an equidigital number, since it uses as much as digits as its factorization.

18985121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23010.

The product of its digits is 5760, while the sum is 35.

The square root of 18985121 is about 4357.1918709187. The cubic root of 18985121 is about 266.7704920361.

The spelling of 18985121 in words is "eighteen million, nine hundred eighty-five thousand, one hundred twenty-one".