18717973 has 4 divisors (see below), whose sum is σ = 18789408. Its totient is φ = 18646540.

The previous prime is 18717971. The next prime is 18717977. The reversal of 18717973 is 37971781.

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 not a de Polignac number, because 18717973 - 2¹ = 18717971 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18717971) 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, 35323 + ... + 35848.

It is an arithmetic number, because the mean of its divisors is an integer number (4697352).

Almost surely, 2^18717973 is an apocalyptic number.

It is an amenable number.

18717973 is a deficient number, since it is larger than the sum of its proper divisors (71435).

18717973 is an equidigital number, since it uses as much as digits as its factorization.

18717973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71434.

The product of its digits is 74088, while the sum is 43.

The square root of 18717973 is about 4326.4272789451. The cubic root of 18717973 is about 265.5132949082.

The spelling of 18717973 in words is "eighteen million, seven hundred seventeen thousand, nine hundred seventy-three".