18471643 has 4 divisors (see below), whose sum is σ = 18505960. Its totient is φ = 18437328.

The previous prime is 18471641. The next prime is 18471647. The reversal of 18471643 is 34617481.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18471643 - 2¹ = 18471641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18471599 and 18471608.

It is not an unprimeable number, because it can be changed into a prime (18471641) 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, 16338 + ... + 17431.

It is an arithmetic number, because the mean of its divisors is an integer number (4626490).

Almost surely, 2^18471643 is an apocalyptic number.

18471643 is a deficient number, since it is larger than the sum of its proper divisors (34317).

18471643 is an equidigital number, since it uses as much as digits as its factorization.

18471643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34316.

The product of its digits is 16128, while the sum is 34.

The square root of 18471643 is about 4297.8649350579. The cubic root of 18471643 is about 264.3434226341.

The spelling of 18471643 in words is "eighteen million, four hundred seventy-one thousand, six hundred forty-three".