18999573 has 4 divisors (see below), whose sum is σ = 25332768. Its totient is φ = 12666380.

The previous prime is 18999551. The next prime is 18999577. The reversal of 18999573 is 37599981.

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, and also an emirpimes, since its reverse is a distinct semiprime: 37599981 = 3 ⋅12533327.

It is a cyclic number.

It is not a de Polignac number, because 18999573 - 2⁸ = 18999317 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18999577) 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, 3166593 + ... + 3166598.

It is an arithmetic number, because the mean of its divisors is an integer number (6333192).

Almost surely, 2^18999573 is an apocalyptic number.

It is an amenable number.

18999573 is a deficient number, since it is larger than the sum of its proper divisors (6333195).

18999573 is an equidigital number, since it uses as much as digits as its factorization.

18999573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6333194.

The product of its digits is 612360, while the sum is 51.

The square root of 18999573 is about 4358.8499630063. The cubic root of 18999573 is about 266.8381658967.

The spelling of 18999573 in words is "eighteen million, nine hundred ninety-nine thousand, five hundred seventy-three".