18642271 has 4 divisors (see below), whose sum is σ = 18947944. Its totient is φ = 18336600.

The previous prime is 18642269. The next prime is 18642311. The reversal of 18642271 is 17224681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17224681 = 883 ⋅19507.

It is not a de Polignac number, because 18642271 - 2¹ = 18642269 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 (18645271) 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, 152745 + ... + 152866.

It is an arithmetic number, because the mean of its divisors is an integer number (4736986).

Almost surely, 2^18642271 is an apocalyptic number.

18642271 is a deficient number, since it is larger than the sum of its proper divisors (305673).

18642271 is an equidigital number, since it uses as much as digits as its factorization.

18642271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305672.

The product of its digits is 5376, while the sum is 31.

The square root of 18642271 is about 4317.6696260830. The cubic root of 18642271 is about 265.1548685359.

The spelling of 18642271 in words is "eighteen million, six hundred forty-two thousand, two hundred seventy-one".