18297840 has 160 divisors (see below), whose sum is σ = 64281600. Its totient is φ = 4264960.

The previous prime is 18297827. The next prime is 18297841. The reversal of 18297840 is 4879281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18297841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76441 + ... + 76679.

It is an arithmetic number, because the mean of its divisors is an integer number (401760).

Almost surely, 2^18297840 is an apocalyptic number.

18297840 is a gapful number since it is divisible by the number (10) 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 18297840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32140800).

18297840 is an abundant number, since it is smaller than the sum of its proper divisors (45983760).

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

18297840 is a wasteful number, since it uses less digits than its factorization.

18297840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 18297840 is about 4277.5974565169. The cubic root of 18297840 is about 263.5117237372.

It can be divided in two parts, 1829 and 7840, that added together give a palindrome (9669).

The spelling of 18297840 in words is "eighteen million, two hundred ninety-seven thousand, eight hundred forty".