221501280 has 384 divisors, whose sum is σ = 938843136. Its totient is φ = 42393600.

The previous prime is 221501243. The next prime is 221501303. The reversal of 221501280 is 82105122.

It is a happy number.

221501280 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 (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 480250 + ... + 480710.

It is an arithmetic number, because the mean of its divisors is an integer number (2444904).

Almost surely, 2^221501280 is an apocalyptic number.

221501280 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 221501280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469421568).

221501280 is an abundant number, since it is smaller than the sum of its proper divisors (717341856).

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

221501280 is a wasteful number, since it uses less digits than its factorization.

221501280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510 (or 502 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 221501280 is about 14882.9190685161. The cubic root of 221501280 is about 605.0511351720.

It can be divided in two parts, 221 and 501280, that added together give a triangular number (501501 = T₁₀₀₁).

The spelling of 221501280 in words is "two hundred twenty-one million, five hundred one thousand, two hundred eighty".