18361121 has 4 divisors (see below), whose sum is σ = 18484500. Its totient is φ = 18237744.

The previous prime is 18361117. The next prime is 18361127. The reversal of 18361121 is 12116381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12116381 = 31 ⋅390851.

It can be written as a sum of positive squares in 2 ways, for example, as 10962721 + 7398400 = 3311^2 + 2720^2 .

It is a cyclic number.

It is not a de Polignac number, because 18361121 - 2² = 18361117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18361127) 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, 61466 + ... + 61763.

It is an arithmetic number, because the mean of its divisors is an integer number (4621125).

Almost surely, 2^18361121 is an apocalyptic number.

It is an amenable number.

18361121 is a deficient number, since it is larger than the sum of its proper divisors (123379).

18361121 is a wasteful number, since it uses less digits than its factorization.

18361121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123378.

The product of its digits is 288, while the sum is 23.

The square root of 18361121 is about 4284.9878646269. The cubic root of 18361121 is about 263.8151493336.

The spelling of 18361121 in words is "eighteen million, three hundred sixty-one thousand, one hundred twenty-one".