211220201202121 has 4 divisors (see below), whose sum is σ = 211229796472452. Its totient is φ = 211210605931792.

The previous prime is 211220201202077. The next prime is 211220201202133. The reversal of 211220201202121 is 121202102022112.

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 147795080410000 + 63425120792121 = 12157100^2 + 7963989^2 .

It is a cyclic number.

It is not a de Polignac number, because 211220201202121 - 2¹³ = 211220201193929 is a prime.

It is a super-2 number, since 2×211220201202121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211220201212121) 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, 4797602146 + ... + 4797646171.

It is an arithmetic number, because the mean of its divisors is an integer number (52807449118113).

Almost surely, 2^{211220201202121} is an apocalyptic number.

It is an amenable number.

211220201202121 is a deficient number, since it is larger than the sum of its proper divisors (9595270331).

211220201202121 is an equidigital number, since it uses as much as digits as its factorization.

211220201202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9595270330.

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

Adding to 211220201202121 its reverse (121202102022112), we get a palindrome (332422303224233).

The spelling of 211220201202121 in words is "two hundred eleven trillion, two hundred twenty billion, two hundred one million, two hundred two thousand, one hundred twenty-one".