18660563 has 4 divisors (see below), whose sum is σ = 18690768. Its totient is φ = 18630360.

The previous prime is 18660559. The next prime is 18660583. The reversal of 18660563 is 36506681.

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

It is a cyclic number.

It is not a de Polignac number, because 18660563 - 2² = 18660559 is a prime.

It is a super-2 number, since 2×18660563² = 696433222953938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18660533) 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, 14156 + ... + 15417.

It is an arithmetic number, because the mean of its divisors is an integer number (4672692).

Almost surely, 2^18660563 is an apocalyptic number.

18660563 is a deficient number, since it is larger than the sum of its proper divisors (30205).

18660563 is an equidigital number, since it uses as much as digits as its factorization.

18660563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30204.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 18660563 is about 4319.7873790269. The cubic root of 18660563 is about 265.2415644711.

The spelling of 18660563 in words is "eighteen million, six hundred sixty thousand, five hundred sixty-three".