18320206438 has 16 divisors (see below), whose sum is σ = 27851489280. Its totient is φ = 9037183176.

The previous prime is 18320206327. The next prime is 18320206447. The reversal of 18320206438 is 83460202381.

It is a junction number, because it is equal to n+sod(n) for n = 18320206397 and 18320206406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156006 + ... + 246937.

It is an arithmetic number, because the mean of its divisors is an integer number (1740718080).

Almost surely, 2^18320206438 is an apocalyptic number.

18320206438 is a deficient number, since it is larger than the sum of its proper divisors (9531282842).

18320206438 is a wasteful number, since it uses less digits than its factorization.

18320206438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403251.

The product of its (nonzero) digits is 55296, while the sum is 37.

The spelling of 18320206438 in words is "eighteen billion, three hundred twenty million, two hundred six thousand, four hundred thirty-eight".