18400406839 has 2 divisors, whose sum is σ = 18400406840. Its totient is φ = 18400406838.

The previous prime is 18400406837. The next prime is 18400406879. The reversal of 18400406839 is 93860400481.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18400406839 - 2¹ = 18400406837 is a prime.

Together with 18400406837, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 18400406795 and 18400406804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18400406831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200203419 + 9200203420.

It is an arithmetic number, because the mean of its divisors is an integer number (9200203420).

Almost surely, 2^18400406839 is an apocalyptic number.

18400406839 is a deficient number, since it is larger than the sum of its proper divisors (1).

18400406839 is an equidigital number, since it uses as much as digits as its factorization.

18400406839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 43.

The spelling of 18400406839 in words is "eighteen billion, four hundred million, four hundred six thousand, eight hundred thirty-nine".