18840047 has 4 divisors (see below), whose sum is σ = 18848760. Its totient is φ = 18831336.

The previous prime is 18840043. The next prime is 18840071. The reversal of 18840047 is 74004881.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18840047 - 2² = 18840043 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18839995 and 18840022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18840043) 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, 1628 + ... + 6350.

It is an arithmetic number, because the mean of its divisors is an integer number (4712190).

Almost surely, 2^18840047 is an apocalyptic number.

18840047 is a deficient number, since it is larger than the sum of its proper divisors (8713).

18840047 is an equidigital number, since it uses as much as digits as its factorization.

18840047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8712.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 18840047 is about 4340.5122969530. The cubic root of 18840047 is about 266.0892486995.

The spelling of 18840047 in words is "eighteen million, eight hundred forty thousand, forty-seven".