221211002121001 has 4 divisors (see below), whose sum is σ = 221526567032004. Its totient is φ = 220895437210000.

The previous prime is 221211002120993. The next prime is 221211002121019. The reversal of 221211002121001 is 100121200112122.

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 97312286360601 + 123898715760400 = 9864699^2 + 11130980^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211002121001 - 2³ = 221211002120993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221211002122001) 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 in 3 ways as a sum of consecutive naturals, for example, 157782454450 + ... + 157782455851.

It is an arithmetic number, because the mean of its divisors is an integer number (55381641758001).

Almost surely, 2^{221211002121001} is an apocalyptic number.

It is an amenable number.

221211002121001 is a deficient number, since it is larger than the sum of its proper divisors (315564911003).

221211002121001 is an equidigital number, since it uses as much as digits as its factorization.

221211002121001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315564911002.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 221211002121001 its reverse (100121200112122), we get a palindrome (321332202233123).

The spelling of 221211002121001 in words is "two hundred twenty-one trillion, two hundred eleven billion, two million, one hundred twenty-one thousand, one".