18313938 has 64 divisors (see below), whose sum is σ = 42508800. Its totient is φ = 5913648.

The previous prime is 18313907. The next prime is 18313949. The reversal of 18313938 is 83931381.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 231783 + ... + 231861.

It is an arithmetic number, because the mean of its divisors is an integer number (664200).

Almost surely, 2^18313938 is an apocalyptic number.

18313938 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18313938, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21254400).

18313938 is an abundant number, since it is smaller than the sum of its proper divisors (24194862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18313938 is an frugal number, since it uses more digits than its factorization.

18313938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 137 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 18313938 is about 4279.4787065716. The cubic root of 18313938 is about 263.5889781805.

The spelling of 18313938 in words is "eighteen million, three hundred thirteen thousand, nine hundred thirty-eight".