18439471 has 2 divisors, whose sum is σ = 18439472. Its totient is φ = 18439470.

The previous prime is 18439457. The next prime is 18439483. The reversal of 18439471 is 17493481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18439471 - 2⁵ = 18439439 is a prime.

It is a super-3 number, since 3×18439471³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18439471.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18439571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9219735 + 9219736.

It is an arithmetic number, because the mean of its divisors is an integer number (9219736).

Almost surely, 2^18439471 is an apocalyptic number.

18439471 is a deficient number, since it is larger than the sum of its proper divisors (1).

18439471 is an equidigital number, since it uses as much as digits as its factorization.

18439471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 37.

The square root of 18439471 is about 4294.1205153093. The cubic root of 18439471 is about 264.1898647586.

The spelling of 18439471 in words is "eighteen million, four hundred thirty-nine thousand, four hundred seventy-one".