18671997 has 4 divisors (see below), whose sum is σ = 24896000. Its totient is φ = 12447996.

The previous prime is 18671993. The next prime is 18672053. The reversal of 18671997 is 79917681.

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 not a de Polignac number, because 18671997 - 2² = 18671993 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 (18671993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3111997 + ... + 3112002.

It is an arithmetic number, because the mean of its divisors is an integer number (6224000).

Almost surely, 2^18671997 is an apocalyptic number.

It is an amenable number.

18671997 is a deficient number, since it is larger than the sum of its proper divisors (6224003).

18671997 is an equidigital number, since it uses as much as digits as its factorization.

18671997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6224002.

The product of its digits is 190512, while the sum is 48.

The square root of 18671997 is about 4321.1106211251. The cubic root of 18671997 is about 265.2957277678.

The spelling of 18671997 in words is "eighteen million, six hundred seventy-one thousand, nine hundred ninety-seven".