221029830 has 128 divisors (see below), whose sum is σ = 682214400. Its totient is φ = 49876992.

The previous prime is 221029819. The next prime is 221029927. The reversal of 221029830 is 38920122.

It is a happy number.

221029830 is digitally balanced in base 2, 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 (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221029794 and 221029803.

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, 156166 + ... + 157574.

It is an arithmetic number, because the mean of its divisors is an integer number (5329800).

Almost surely, 2^221029830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221029830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (341107200).

221029830 is an abundant number, since it is smaller than the sum of its proper divisors (461184570).

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

221029830 is a wasteful number, since it uses less digits than its factorization.

221029830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515 (or 1509 counting only the distinct ones).

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

The square root of 221029830 is about 14867.0720049376. The cubic root of 221029830 is about 604.6215605641.

Adding to 221029830 its reverse (38920122), we get a palindrome (259949952).

The spelling of 221029830 in words is "two hundred twenty-one million, twenty-nine thousand, eight hundred thirty".