18489938 has 4 divisors (see below), whose sum is σ = 27734910. Its totient is φ = 9244968.

The previous prime is 18489937. The next prime is 18489943. The reversal of 18489938 is 83998481.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18037009 + 452929 = 4247^2 + 673^2 .

It is not an unprimeable number, because it can be changed into a prime (18489937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4622483 + ... + 4622486.

Almost surely, 2^18489938 is an apocalyptic number.

18489938 is a deficient number, since it is larger than the sum of its proper divisors (9244972).

18489938 is an equidigital number, since it uses as much as digits as its factorization.

18489938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9244971.

The product of its digits is 497664, while the sum is 50.

The square root of 18489938 is about 4299.9927906916. The cubic root of 18489938 is about 264.4306656794.

The spelling of 18489938 in words is "eighteen million, four hundred eighty-nine thousand, nine hundred thirty-eight".