18906227 has 4 divisors (see below), whose sum is σ = 20018376. Its totient is φ = 17794080.

The previous prime is 18906221. The next prime is 18906241. The reversal of 18906227 is 72260981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72260981 = 13 ⋅5558537.

It is a cyclic number.

It is not a de Polignac number, because 18906227 - 2⁴ = 18906211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18906221) 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, 556049 + ... + 556082.

It is an arithmetic number, because the mean of its divisors is an integer number (5004594).

Almost surely, 2^18906227 is an apocalyptic number.

18906227 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

18906227 is a deficient number, since it is larger than the sum of its proper divisors (1112149).

18906227 is a wasteful number, since it uses less digits than its factorization.

18906227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112148.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 18906227 is about 4348.1291379167. The cubic root of 18906227 is about 266.4004511636.

The spelling of 18906227 in words is "eighteen million, nine hundred six thousand, two hundred twenty-seven".