221655330 has 192 divisors, whose sum is σ = 668304000. Its totient is φ = 50813568.

The previous prime is 221655319. The next prime is 221655331. The reversal of 221655330 is 33556122.

221655330 is a `hidden beast` number, since 2 + 2 + 1 + 655 + 3 + 3 + 0 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 221655294 and 221655303.

It is not an unprimeable number, because it can be changed into a prime (221655331) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3756841 + ... + 3756899.

It is an arithmetic number, because the mean of its divisors is an integer number (3480750).

Almost surely, 2^221655330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221655330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334152000).

221655330 is an abundant number, since it is smaller than the sum of its proper divisors (446648670).

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

221655330 is a wasteful number, since it uses less digits than its factorization.

221655330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 221655330 is about 14888.0935649935. The cubic root of 221655330 is about 605.1913699185.

It can be divided in two parts, 22165 and 5330, that added together give a triangular number (27495 = T₂₃₄).

The spelling of 221655330 in words is "two hundred twenty-one million, six hundred fifty-five thousand, three hundred thirty".