18121472 has 36 divisors (see below), whose sum is σ = 36718416. Its totient is φ = 8924160.

The previous prime is 18121469. The next prime is 18121517. The reversal of 18121472 is 27412181.

It is an alternating number because its digits alternate between odd and even.

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, 17678 + ... + 18674.

It is an arithmetic number, because the mean of its divisors is an integer number (1019956).

Almost surely, 2^18121472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18121472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18359208).

18121472 is an abundant number, since it is smaller than the sum of its proper divisors (18596944).

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

18121472 is an frugal number, since it uses more digits than its factorization.

18121472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084 (or 1070 counting only the distinct ones).

The product of its digits is 896, while the sum is 26.

The square root of 18121472 is about 4256.9322287300. The cubic root of 18121472 is about 262.6623491550.

The spelling of 18121472 in words is "eighteen million, one hundred twenty-one thousand, four hundred seventy-two".