221451930 has 96 divisors (see below), whose sum is σ = 660576384. Its totient is φ = 50421888.

The previous prime is 221451929. The next prime is 221451949. The reversal of 221451930 is 39154122.

221451930 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221451894 and 221451903.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 218104 + ... + 219116.

It is an arithmetic number, because the mean of its divisors is an integer number (6881004).

Almost surely, 2^221451930 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221451930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330288192).

221451930 is an abundant number, since it is smaller than the sum of its proper divisors (439124454).

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

221451930 is a wasteful number, since it uses less digits than its factorization.

221451930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1380 (or 1377 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 221451930 is about 14881.2610352752. The cubic root of 221451930 is about 605.0061971453.

The spelling of 221451930 in words is "two hundred twenty-one million, four hundred fifty-one thousand, nine hundred thirty".