18115661 has 8 divisors (see below), whose sum is σ = 18539520. Its totient is φ = 17696448.

The previous prime is 18115639. The next prime is 18115667. The reversal of 18115661 is 16651181.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18115661 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 (18115667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7445 + ... + 9573.

It is an arithmetic number, because the mean of its divisors is an integer number (2317440).

Almost surely, 2^18115661 is an apocalyptic number.

It is an amenable number.

18115661 is a deficient number, since it is larger than the sum of its proper divisors (423859).

18115661 is a wasteful number, since it uses less digits than its factorization.

18115661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2323.

The product of its digits is 1440, while the sum is 29.

The square root of 18115661 is about 4256.2496402349. The cubic root of 18115661 is about 262.6342702350.

The spelling of 18115661 in words is "eighteen million, one hundred fifteen thousand, six hundred sixty-one".