18720338 has 16 divisors (see below), whose sum is σ = 34560960. Its totient is φ = 7405776.

The previous prime is 18720337. The next prime is 18720343. The reversal of 18720338 is 83302781.

It is not an unprimeable number, because it can be changed into a prime (18720337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51248 + ... + 51611.

It is an arithmetic number, because the mean of its divisors is an integer number (2160060).

Almost surely, 2^18720338 is an apocalyptic number.

18720338 is a deficient number, since it is larger than the sum of its proper divisors (15840622).

18720338 is a wasteful number, since it uses less digits than its factorization.

18720338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102881.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 18720338 is about 4326.7005905193. The cubic root of 18720338 is about 265.5244768971.

The spelling of 18720338 in words is "eighteen million, seven hundred twenty thousand, three hundred thirty-eight".