18121938 has 8 divisors (see below), whose sum is σ = 36243888. Its totient is φ = 6040644.

The previous prime is 18121921. The next prime is 18121973. The reversal of 18121938 is 83912181.

It is a sphenic number, since it is the product of 3 distinct primes.

18121938 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 18121899 and 18121908.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1510156 + ... + 1510167.

It is an arithmetic number, because the mean of its divisors is an integer number (4530486).

Almost surely, 2^18121938 is an apocalyptic number.

18121938 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18121938 is a wasteful number, since it uses less digits than its factorization.

18121938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3020328.

The product of its digits is 3456, while the sum is 33.

The square root of 18121938 is about 4256.9869626298. The cubic root of 18121938 is about 262.6646006205.

The spelling of 18121938 in words is "eighteen million, one hundred twenty-one thousand, nine hundred thirty-eight".