202121100121 has 4 divisors (see below), whose sum is σ = 202122144000. Its totient is φ = 202120056244.

The previous prime is 202121100101. The next prime is 202121100127. The reversal of 202121100121 is 121001121202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 202121100121 - 2¹³ = 202121091929 is a prime.

It is a super-2 number, since 2×202121100121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (202121100127) 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, 136741 + ... + 650338.

It is an arithmetic number, because the mean of its divisors is an integer number (50530536000).

Almost surely, 2^202121100121 is an apocalyptic number.

It is an amenable number.

202121100121 is a deficient number, since it is larger than the sum of its proper divisors (1043879).

202121100121 is an equidigital number, since it uses as much as digits as its factorization.

202121100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1043878.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 202121100121 its reverse (121001121202), we get a palindrome (323122221323).

The spelling of 202121100121 in words is "two hundred two billion, one hundred twenty-one million, one hundred thousand, one hundred twenty-one".