18121968 has 120 divisors (see below), whose sum is σ = 54163200. Its totient is φ = 5863104.

The previous prime is 18121921. The next prime is 18121973. The reversal of 18121968 is 86912181.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 229353 + ... + 229431.

It is an arithmetic number, because the mean of its divisors is an integer number (451360).

Almost surely, 2^18121968 is an apocalyptic number.

18121968 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18121968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27081600).

18121968 is an abundant number, since it is smaller than the sum of its proper divisors (36041232).

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

18121968 is an equidigital number, since it uses as much as digits as its factorization.

18121968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161 (or 143 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 18121968 is about 4256.9904862473. The cubic root of 18121968 is about 262.6647455633.

The spelling of 18121968 in words is "eighteen million, one hundred twenty-one thousand, nine hundred sixty-eight".