18992217 has 4 divisors (see below), whose sum is σ = 25322960. Its totient is φ = 12661476.

The previous prime is 18992209. The next prime is 18992219. The reversal of 18992217 is 71229981.

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: 71229981 = 3 ⋅23743327.

It is not a de Polignac number, because 18992217 - 2³ = 18992209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18992219) 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, 3165367 + ... + 3165372.

It is an arithmetic number, because the mean of its divisors is an integer number (6330740).

Almost surely, 2^18992217 is an apocalyptic number.

It is an amenable number.

18992217 is a deficient number, since it is larger than the sum of its proper divisors (6330743).

18992217 is an equidigital number, since it uses as much as digits as its factorization.

18992217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6330742.

The product of its digits is 18144, while the sum is 39.

The square root of 18992217 is about 4358.0060807668. The cubic root of 18992217 is about 266.8037245100.

The spelling of 18992217 in words is "eighteen million, nine hundred ninety-two thousand, two hundred seventeen".