221944830 has 64 divisors (see below), whose sum is σ = 553400640. Its totient is φ = 56899584.

The previous prime is 221944829. The next prime is 221944861. The reversal of 221944830 is 38449122.

It is a Curzon number.

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 221944791 and 221944800.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 292812 + ... + 293568.

It is an arithmetic number, because the mean of its divisors is an integer number (8646885).

Almost surely, 2^221944830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221944830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276700320).

221944830 is an abundant number, since it is smaller than the sum of its proper divisors (331455810).

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

221944830 is a wasteful number, since it uses less digits than its factorization.

221944830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1133.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 221944830 is about 14897.8129267353. The cubic root of 221944830 is about 605.4547317792.

The spelling of 221944830 in words is "two hundred twenty-one million, nine hundred forty-four thousand, eight hundred thirty".