221021113 has 4 divisors (see below), whose sum is σ = 221677300. Its totient is φ = 220364928.

The previous prime is 221021111. The next prime is 221021137. The reversal of 221021113 is 311120122.

221021113 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 50013184 + 171007929 = 7072^2 + 13077^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021113 - 2¹ = 221021111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221021093 and 221021102.

It is not an unprimeable number, because it can be changed into a prime (221021111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327588 + ... + 328261.

It is an arithmetic number, because the mean of its divisors is an integer number (55419325).

Almost surely, 2^221021113 is an apocalyptic number.

It is an amenable number.

221021113 is a deficient number, since it is larger than the sum of its proper divisors (656187).

221021113 is an equidigital number, since it uses as much as digits as its factorization.

221021113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656186.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 221021113 is about 14866.7788373945. The cubic root of 221021113 is about 604.6136120813.

Adding to 221021113 its reverse (311120122), we get a palindrome (532141235).

Subtracting 221021113 from its reverse (311120122), we obtain a palindrome (90099009).

The spelling of 221021113 in words is "two hundred twenty-one million, twenty-one thousand, one hundred thirteen".