221309235 has 72 divisors (see below), whose sum is σ = 449650656. Its totient is φ = 100396800.

The previous prime is 221309233. The next prime is 221309287. The reversal of 221309235 is 532903122.

221309235 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221309235 - 2¹ = 221309233 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221309199 and 221309208.

It is not an unprimeable number, because it can be changed into a prime (221309233) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 367935 + ... + 368535.

It is an arithmetic number, because the mean of its divisors is an integer number (6245148).

Almost surely, 2^221309235 is an apocalyptic number.

221309235 is an abundant number, since it is smaller than the sum of its proper divisors (228341421).

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

221309235 is a wasteful number, since it uses less digits than its factorization.

221309235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793 (or 783 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 221309235 is about 14876.4658101311. The cubic root of 221309235 is about 604.8762217464.

The spelling of 221309235 in words is "two hundred twenty-one million, three hundred nine thousand, two hundred thirty-five".