18661121 has 8 divisors (see below), whose sum is σ = 19945440. Its totient is φ = 17397568.

The previous prime is 18661099. The next prime is 18661129. The reversal of 18661121 is 12116681.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18661121 - 2⁶ = 18661057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18661129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3311 + ... + 6948.

It is an arithmetic number, because the mean of its divisors is an integer number (2493180).

Almost surely, 2^18661121 is an apocalyptic number.

It is an amenable number.

18661121 is a deficient number, since it is larger than the sum of its proper divisors (1284319).

18661121 is a wasteful number, since it uses less digits than its factorization.

18661121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10383.

The product of its digits is 576, while the sum is 26.

The square root of 18661121 is about 4319.8519650562. The cubic root of 18661121 is about 265.2442082520.

The spelling of 18661121 in words is "eighteen million, six hundred sixty-one thousand, one hundred twenty-one".