18217472 has 160 divisors (see below), whose sum is σ = 49496832. Its totient is φ = 6488064.

The previous prime is 18217457. The next prime is 18217477. The reversal of 18217472 is 27471281.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

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

It is not an unprimeable number, because it can be changed into a prime (18217477) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 792053 + ... + 792075.

Almost surely, 2^18217472 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 18217472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24748416).

18217472 is an abundant number, since it is smaller than the sum of its proper divisors (31279360).

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

18217472 is a wasteful number, since it uses less digits than its factorization.

18217472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 62 counting only the distinct ones).

The product of its digits is 6272, while the sum is 32.

The square root of 18217472 is about 4268.1930603008. The cubic root of 18217472 is about 263.1253576952.

The spelling of 18217472 in words is "eighteen million, two hundred seventeen thousand, four hundred seventy-two".