202121101221 has 64 divisors (see below), whose sum is σ = 295913399040. Its totient is φ = 121974128640.

The previous prime is 202121101219. The next prime is 202121101277. The reversal of 202121101221 is 122101121202.

It is not a de Polignac number, because 202121101221 - 2¹ = 202121101219 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 202121101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121101421) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 249840265 + ... + 249841073.

It is an arithmetic number, because the mean of its divisors is an integer number (4623646860).

Almost surely, 2^202121101221 is an apocalyptic number.

It is an amenable number.

202121101221 is a deficient number, since it is larger than the sum of its proper divisors (93792297819).

202121101221 is a wasteful number, since it uses less digits than its factorization.

202121101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1446.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 202121101221 its reverse (122101121202), we get a palindrome (324222222423).

The spelling of 202121101221 in words is "two hundred two billion, one hundred twenty-one million, one hundred one thousand, two hundred twenty-one".