221630280 has 64 divisors (see below), whose sum is σ = 668304000. Its totient is φ = 58798080.

The previous prime is 221630257. The next prime is 221630281. The reversal of 221630280 is 82036122.

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

It is a self number, because there is not a number n which added to its sum of digits gives 221630280.

It is not an unprimeable number, because it can be changed into a prime (221630281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19240 + ... + 28520.

It is an arithmetic number, because the mean of its divisors is an integer number (10442250).

Almost surely, 2^221630280 is an apocalyptic number.

221630280 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 221630280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334152000).

221630280 is an abundant number, since it is smaller than the sum of its proper divisors (446673720).

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

221630280 is a wasteful number, since it uses less digits than its factorization.

221630280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9494 (or 9490 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 221630280 is about 14887.2522649413. The cubic root of 221630280 is about 605.1685708353.

The spelling of 221630280 in words is "two hundred twenty-one million, six hundred thirty thousand, two hundred eighty".