18661313 has 8 divisors (see below), whose sum is σ = 20420640. Its totient is φ = 16912480.

The previous prime is 18661289. The next prime is 18661327. The reversal of 18661313 is 31316681.

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 18661313 - 2⁸ = 18661057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (18661333) 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, 1373 + ... + 6261.

It is an arithmetic number, because the mean of its divisors is an integer number (2552580).

Almost surely, 2^18661313 is an apocalyptic number.

It is an amenable number.

18661313 is a deficient number, since it is larger than the sum of its proper divisors (1759327).

18661313 is a wasteful number, since it uses less digits than its factorization.

18661313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5247.

The product of its digits is 2592, while the sum is 29.

The square root of 18661313 is about 4319.8741879828. The cubic root of 18661313 is about 265.2451179278.

Adding to 18661313 its reverse (31316681), we get a palindrome (49977994).

The spelling of 18661313 in words is "eighteen million, six hundred sixty-one thousand, three hundred thirteen".