18215712 has 96 divisors (see below), whose sum is σ = 55036800. Its totient is φ = 5854464.

The previous prime is 18215711. The next prime is 18215731. The reversal of 18215712 is 21751281.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18215711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24693 + ... + 25419.

It is an arithmetic number, because the mean of its divisors is an integer number (573300).

Almost surely, 2^18215712 is an apocalyptic number.

18215712 is a gapful number since it is divisible by the number (12) 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 18215712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27518400).

18215712 is an abundant number, since it is smaller than the sum of its proper divisors (36821088).

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

18215712 is a wasteful number, since it uses less digits than its factorization.

18215712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775 (or 761 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 18215712 is about 4267.9868790801. The cubic root of 18215712 is about 263.1168838604.

Adding to 18215712 its reverse (21751281), we get a palindrome (39966993).

The spelling of 18215712 in words is "eighteen million, two hundred fifteen thousand, seven hundred twelve".