18604661 has 2 divisors, whose sum is σ = 18604662. Its totient is φ = 18604660.

The previous prime is 18604633. The next prime is 18604687. The reversal of 18604661 is 16640681.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18576100 + 28561 = 4310^2 + 169^2 .

It is an emirp because it is prime and its reverse (16640681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18604661 - 2¹⁴ = 18588277 is a prime.

It is a super-2 number, since 2×18604661² = 692266821849842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18604361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9302330 + 9302331.

It is an arithmetic number, because the mean of its divisors is an integer number (9302331).

Almost surely, 2^18604661 is an apocalyptic number.

It is an amenable number.

18604661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18604661 is an equidigital number, since it uses as much as digits as its factorization.

18604661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 18604661 is about 4313.3120684690. The cubic root of 18604661 is about 264.9764355456.

The spelling of 18604661 in words is "eighteen million, six hundred four thousand, six hundred sixty-one".