18434639 has 2 divisors, whose sum is σ = 18434640. Its totient is φ = 18434638.

The previous prime is 18434567. The next prime is 18434641. The reversal of 18434639 is 93643481.

It is a strong prime.

It is an emirp because it is prime and its reverse (93643481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18434639 - 2¹² = 18430543 is a prime.

Together with 18434641, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18434699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9217319 + 9217320.

It is an arithmetic number, because the mean of its divisors is an integer number (9217320).

Almost surely, 2^18434639 is an apocalyptic number.

18434639 is a deficient number, since it is larger than the sum of its proper divisors (1).

18434639 is an equidigital number, since it uses as much as digits as its factorization.

18434639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 38.

The square root of 18434639 is about 4293.5578486845. The cubic root of 18434639 is about 264.1667860606.

The spelling of 18434639 in words is "eighteen million, four hundred thirty-four thousand, six hundred thirty-nine".