221010101 has 8 divisors (see below), whose sum is σ = 238268184. Its totient is φ = 203788800.

The previous prime is 221010091. The next prime is 221010107. The reversal of 221010101 is 101010122.

221010101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 51984100 + 169026001 = 7210^2 + 13001^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221010101 - 2⁶ = 221010037 is a prime.

It is a Duffinian number.

221010101 is a modest number, since divided by 10101 gives 221 as remainder.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221010107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4001 + ... + 21401.

It is an arithmetic number, because the mean of its divisors is an integer number (29783523).

Almost surely, 2^221010101 is an apocalyptic number.

It is an amenable number.

221010101 is a deficient number, since it is larger than the sum of its proper divisors (17258083).

221010101 is a wasteful number, since it uses less digits than its factorization.

221010101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18391.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 221010101 is about 14866.4084768312. The cubic root of 221010101 is about 604.6035706338.

Adding to 221010101 its reverse (101010122), we get a palindrome (322020223).

It can be divided in two parts, 22 and 1010101, that multiplied together give a palindrome (22222222).

The spelling of 221010101 in words is "two hundred twenty-one million, ten thousand, one hundred one".