210121212220201 has 4 divisors (see below), whose sum is σ = 210274250249412. Its totient is φ = 209968174190992.

The previous prime is 210121212220189. The next prime is 210121212220211. The reversal of 210121212220201 is 102022212121012.

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 114569707468176 + 95551504752025 = 10703724^2 + 9775045^2 .

It is a cyclic number.

It is not a de Polignac number, because 210121212220201 - 2⁵ = 210121212220169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210121212220211) 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, 76519012546 + ... + 76519015291.

It is an arithmetic number, because the mean of its divisors is an integer number (52568562562353).

Almost surely, 2^{210121212220201} is an apocalyptic number.

It is an amenable number.

210121212220201 is a deficient number, since it is larger than the sum of its proper divisors (153038029211).

210121212220201 is a wasteful number, since it uses less digits than its factorization.

210121212220201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153038029210.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 210121212220201 its reverse (102022212121012), we get a palindrome (312143424341213).

The spelling of 210121212220201 in words is "two hundred ten trillion, one hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, two hundred one".