221560900 has 72 divisors (see below), whose sum is σ = 552152160. Its totient is φ = 76320000.

The previous prime is 221560891. The next prime is 221560903. The reversal of 221560900 is 9065122.

221560900 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (221560903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15600 + ... + 26200.

It is an arithmetic number, because the mean of its divisors is an integer number (7668780).

Almost surely, 2^221560900 is an apocalyptic number.

221560900 is a gapful number since it is divisible by the number (20) 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 221560900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276076080).

221560900 is an abundant number, since it is smaller than the sum of its proper divisors (330591260).

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

221560900 is a wasteful number, since it uses less digits than its factorization.

221560900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10645 (or 10638 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 221560900 is about 14884.9219010380. The cubic root of 221560900 is about 605.1054161415.

The spelling of 221560900 in words is "two hundred twenty-one million, five hundred sixty thousand, nine hundred".