18299561 has 4 divisors (see below), whose sum is σ = 20913792. Its totient is φ = 15685332.

The previous prime is 18299549. The next prime is 18299621. The reversal of 18299561 is 16599281.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18299561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18299861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1307105 + ... + 1307118.

It is an arithmetic number, because the mean of its divisors is an integer number (5228448).

Almost surely, 2^18299561 is an apocalyptic number.

It is an amenable number.

18299561 is a deficient number, since it is larger than the sum of its proper divisors (2614231).

18299561 is an equidigital number, since it uses as much as digits as its factorization.

18299561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2614230.

The product of its digits is 38880, while the sum is 41.

The square root of 18299561 is about 4277.7986161109. The cubic root of 18299561 is about 263.5199849938.

The spelling of 18299561 in words is "eighteen million, two hundred ninety-nine thousand, five hundred sixty-one".