18850561 has 4 divisors (see below), whose sum is σ = 18877012. Its totient is φ = 18824112.

The previous prime is 18850549. The next prime is 18850567. The reversal of 18850561 is 16505881.

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 15752961 + 3097600 = 3969^2 + 1760^2 .

It is a cyclic number.

It is not a de Polignac number, because 18850561 - 2⁹ = 18850049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18850567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12126 + ... + 13591.

It is an arithmetic number, because the mean of its divisors is an integer number (4719253).

Almost surely, 2^18850561 is an apocalyptic number.

It is an amenable number.

18850561 is a deficient number, since it is larger than the sum of its proper divisors (26451).

18850561 is an equidigital number, since it uses as much as digits as its factorization.

18850561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26450.

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 18850561 is about 4341.7232753827. The cubic root of 18850561 is about 266.1387379974.

The spelling of 18850561 in words is "eighteen million, eight hundred fifty thousand, five hundred sixty-one".