220840 has 16 divisors (see below), whose sum is σ = 496980. Its totient is φ = 88320.

The previous prime is 220811. The next prime is 220841. The reversal of 220840 is 48022.

It can be written as a sum of positive squares in 2 ways, for example, as 213444 + 7396 = 462^2 + 86^2 .

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (220841) by changing a digit.

220840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2721 + ... + 2800.

2²²⁰⁸⁴⁰ is an apocalyptic number.

220840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

220840 is an abundant number, since it is smaller than the sum of its proper divisors (276140).

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

220840 is a wasteful number, since it uses less digits than its factorization.

220840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5532 (or 5528 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 220840 is about 469.9361658779. The cubic root of 220840 is about 60.4448419252. Note that the first 3 decimals are identical.

Adding to 220840 its reverse (48022), we get a palindrome (268862).

The spelling of 220840 in words is "two hundred twenty thousand, eight hundred forty".