18221760 has 280 divisors, whose sum is σ = 70073520. Its totient is φ = 4478976.

The previous prime is 18221743. The next prime is 18221761. The reversal of 18221760 is 6712281.

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

It is not an unprimeable number, because it can be changed into a prime (18221761) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 492462 + ... + 492498.

Almost surely, 2^18221760 is an apocalyptic number.

18221760 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 18221760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35036760).

18221760 is an abundant number, since it is smaller than the sum of its proper divisors (51851760).

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

18221760 is a wasteful number, since it uses less digits than its factorization.

18221760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 18221760 is about 4268.6953510411. The cubic root of 18221760 is about 263.1460007537.

It can be divided in two parts, 18221 and 760, that added together give a palindrome (18981).

The spelling of 18221760 in words is "eighteen million, two hundred twenty-one thousand, seven hundred sixty".