221930280 has 320 divisors, whose sum is σ = 878169600. Its totient is φ = 49559040.

The previous prime is 221930251. The next prime is 221930281. The reversal of 221930280 is 82039122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221930281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 463081 + ... + 463559.

It is an arithmetic number, because the mean of its divisors is an integer number (2744280).

Almost surely, 2^221930280 is an apocalyptic number.

221930280 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 221930280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (439084800).

221930280 is an abundant number, since it is smaller than the sum of its proper divisors (656239320).

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

221930280 is a wasteful number, since it uses less digits than its factorization.

221930280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 221930280 is about 14897.3245920199. The cubic root of 221930280 is about 605.4415009253.

The spelling of 221930280 in words is "two hundred twenty-one million, nine hundred thirty thousand, two hundred eighty".