18895561 has 4 divisors (see below), whose sum is σ = 18906624. Its totient is φ = 18884500.

The previous prime is 18895537. The next prime is 18895589. The reversal of 18895561 is 16559881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18895561 - 2⁵ = 18895529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18895511) 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, 2365 + ... + 6586.

It is an arithmetic number, because the mean of its divisors is an integer number (4726656).

Almost surely, 2^18895561 is an apocalyptic number.

It is an amenable number.

18895561 is a deficient number, since it is larger than the sum of its proper divisors (11063).

18895561 is an equidigital number, since it uses as much as digits as its factorization.

18895561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11062.

The product of its digits is 86400, while the sum is 43.

The square root of 18895561 is about 4346.9024603734. The cubic root of 18895561 is about 266.3503448906.

The spelling of 18895561 in words is "eighteen million, eight hundred ninety-five thousand, five hundred sixty-one".