18508973 has 4 divisors (see below), whose sum is σ = 21153120. Its totient is φ = 15864828.

The previous prime is 18508969. The next prime is 18508979. The reversal of 18508973 is 37980581.

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: 37980581 = 283 ⋅134207.

It is not a de Polignac number, because 18508973 - 2² = 18508969 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18508973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18508979) 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, 1322063 + ... + 1322076.

It is an arithmetic number, because the mean of its divisors is an integer number (5288280).

Almost surely, 2^18508973 is an apocalyptic number.

It is an amenable number.

18508973 is a deficient number, since it is larger than the sum of its proper divisors (2644147).

18508973 is an equidigital number, since it uses as much as digits as its factorization.

18508973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644146.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 18508973 is about 4302.2055971327. The cubic root of 18508973 is about 264.5213764835.

The spelling of 18508973 in words is "eighteen million, five hundred eight thousand, nine hundred seventy-three".