18694661 has 4 divisors (see below), whose sum is σ = 18725772. Its totient is φ = 18663552.

The previous prime is 18694619. The next prime is 18694691. The reversal of 18694661 is 16649681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5262436 + 13432225 = 2294^2 + 3665^2 .

It is a cyclic number.

It is not a de Polignac number, because 18694661 - 2¹⁰ = 18693637 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 (18694601) 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, 14636 + ... + 15861.

It is an arithmetic number, because the mean of its divisors is an integer number (4681443).

Almost surely, 2^18694661 is an apocalyptic number.

It is an amenable number.

18694661 is a deficient number, since it is larger than the sum of its proper divisors (31111).

18694661 is an equidigital number, since it uses as much as digits as its factorization.

18694661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31110.

The product of its digits is 62208, while the sum is 41.

The square root of 18694661 is about 4323.7322997614. The cubic root of 18694661 is about 265.4030226882.

The spelling of 18694661 in words is "eighteen million, six hundred ninety-four thousand, six hundred sixty-one".