221916980 has 72 divisors (see below), whose sum is σ = 506612232. Its totient is φ = 81371136.

The previous prime is 221916977. The next prime is 221916991. The reversal of 221916980 is 89619122.

It can be written as a sum of positive squares in 4 ways, for example, as 37283236 + 184633744 = 6106^2 + 13588^2 .

It is a super-3 number, since 3×221916980³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 628484 + ... + 628836.

It is an arithmetic number, because the mean of its divisors is an integer number (7036281).

Almost surely, 2^221916980 is an apocalyptic number.

221916980 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 221916980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253306116).

221916980 is an abundant number, since it is smaller than the sum of its proper divisors (284695252).

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

221916980 is a wasteful number, since it uses less digits than its factorization.

221916980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 221916980 is about 14896.8781964545. The cubic root of 221916980 is about 605.4294062368.

The spelling of 221916980 in words is "two hundred twenty-one million, nine hundred sixteen thousand, nine hundred eighty".