21600220 has 24 divisors (see below), whose sum is σ = 47333664. Its totient is φ = 8264256.

The previous prime is 21600209. The next prime is 21600239. The reversal of 21600220 is 2200612.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21600220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23019 + ... + 23938.

It is an arithmetic number, because the mean of its divisors is an integer number (1972236).

Almost surely, 2^21600220 is an apocalyptic number.

21600220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21600220 is an abundant number, since it is smaller than the sum of its proper divisors (25733444).

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

21600220 is a wasteful number, since it uses less digits than its factorization.

21600220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46989 (or 46987 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21600220 is about 4647.6036836202. The cubic root of 21600220 is about 278.4962755224.

Adding to 21600220 its reverse (2200612), we get a palindrome (23800832).

The spelling of 21600220 in words is "twenty-one million, six hundred thousand, two hundred twenty".