18668653 has 4 divisors (see below), whose sum is σ = 19124028. Its totient is φ = 18213280.

The previous prime is 18668641. The next prime is 18668687. The reversal of 18668653 is 35686681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35686681 = 59 ⋅604859.

It can be written as a sum of positive squares in 2 ways, for example, as 2812329 + 15856324 = 1677^2 + 3982^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18668653 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 (18668693) 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, 227626 + ... + 227707.

It is an arithmetic number, because the mean of its divisors is an integer number (4781007).

Almost surely, 2^18668653 is an apocalyptic number.

It is an amenable number.

18668653 is a deficient number, since it is larger than the sum of its proper divisors (455375).

18668653 is an equidigital number, since it uses as much as digits as its factorization.

18668653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455374.

The product of its digits is 207360, while the sum is 43.

The square root of 18668653 is about 4320.7236662393. The cubic root of 18668653 is about 265.2798893998.

It can be divided in two parts, 18668 and 653, that added together give a square (19321 = 139²).

The spelling of 18668653 in words is "eighteen million, six hundred sixty-eight thousand, six hundred fifty-three".