221020121200121 has 4 divisors (see below), whose sum is σ = 221020156758372. Its totient is φ = 221020085641872.

The previous prime is 221020121200117. The next prime is 221020121200171. The reversal of 221020121200121 is 121002121020122.

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 81098760085225 + 139921361114896 = 9005485^2 + 11828836^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020121200121 - 2² = 221020121200117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221020121200121.

It is not an unprimeable number, because it can be changed into a prime (221020121200171) 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, 5736566 + ... + 21793311.

It is an arithmetic number, because the mean of its divisors is an integer number (55255039189593).

Almost surely, 2^{221020121200121} is an apocalyptic number.

It is an amenable number.

221020121200121 is a deficient number, since it is larger than the sum of its proper divisors (35558251).

221020121200121 is an equidigital number, since it uses as much as digits as its factorization.

221020121200121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35558250.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221020121200121 its reverse (121002121020122), we get a palindrome (342022242220243).

The spelling of 221020121200121 in words is "two hundred twenty-one trillion, twenty billion, one hundred twenty-one million, two hundred thousand, one hundred twenty-one".