221550720 has 256 divisors, whose sum is σ = 766713600. Its totient is φ = 54247424.

The previous prime is 221550713. The next prime is 221550727. The reversal of 221550720 is 27055122.

It is an interprime number because it is at equal distance from previous prime (221550713) and next prime (221550727).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221550727) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1280554 + ... + 1280726.

It is an arithmetic number, because the mean of its divisors is an integer number (2994975).

Almost surely, 2^221550720 is an apocalyptic number.

221550720 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 221550720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383356800).

221550720 is an abundant number, since it is smaller than the sum of its proper divisors (545162880).

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

221550720 is a wasteful number, since it uses less digits than its factorization.

221550720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 221550720 is about 14884.5799403275. The cubic root of 221550720 is about 605.0961484601.

The spelling of 221550720 in words is "two hundred twenty-one million, five hundred fifty thousand, seven hundred twenty".