221123523121 has 2 divisors, whose sum is σ = 221123523122. Its totient is φ = 221123523120.

The previous prime is 221123523119. The next prime is 221123523161. The reversal of 221123523121 is 121325321122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186922199025 + 34201324096 = 432345^2 + 184936^2 .

It is a cyclic number.

It is not a de Polignac number, because 221123523121 - 2¹ = 221123523119 is a prime.

It is a super-2 number, since 2×221123523121² (a number of 23 digits) contains 22 as substring.

Together with 221123523119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221123523161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110561761560 + 110561761561.

It is an arithmetic number, because the mean of its divisors is an integer number (110561761561).

Almost surely, 2^221123523121 is an apocalyptic number.

It is an amenable number.

221123523121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221123523121 is an equidigital number, since it uses as much as digits as its factorization.

221123523121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

Adding to 221123523121 its reverse (121325321122), we get a palindrome (342448844243).

The spelling of 221123523121 in words is "two hundred twenty-one billion, one hundred twenty-three million, five hundred twenty-three thousand, one hundred twenty-one".