221012202121 has 4 divisors (see below), whose sum is σ = 221014244500. Its totient is φ = 221010159744.

The previous prime is 221012202109. The next prime is 221012202133. The reversal of 221012202121 is 121202210122.

It is a happy number.

221012202121 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 is an interprime number because it is at equal distance from previous prime (221012202109) and next prime (221012202133).

It can be written as a sum of positive squares in 2 ways, for example, as 50142405625 + 170869796496 = 223925^2 + 413364^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012202121 - 2⁹ = 221012201609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221012202095 and 221012202104.

It is not an unprimeable number, because it can be changed into a prime (221012208121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 849216 + ... + 1078513.

It is an arithmetic number, because the mean of its divisors is an integer number (55253561125).

Almost surely, 2^221012202121 is an apocalyptic number.

It is an amenable number.

221012202121 is a deficient number, since it is larger than the sum of its proper divisors (2042379).

221012202121 is a wasteful number, since it uses less digits than its factorization.

221012202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2042378.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221012202121 its reverse (121202210122), we get a palindrome (342214412243).

It can be divided in two parts, 22101 and 2202121, that added together give a palindrome (2224222).

The spelling of 221012202121 in words is "two hundred twenty-one billion, twelve million, two hundred two thousand, one hundred twenty-one".