202121191 has 2 divisors, whose sum is σ = 202121192. Its totient is φ = 202121190.

The previous prime is 202121189. The next prime is 202121203. The reversal of 202121191 is 191121202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 202121191 - 2¹ = 202121189 is a prime.

Together with 202121189, it forms a pair of twin primes.

It is a Chen prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202124191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060595 + 101060596.

It is an arithmetic number, because the mean of its divisors is an integer number (101060596).

Almost surely, 2^202121191 is an apocalyptic number.

202121191 is a deficient number, since it is larger than the sum of its proper divisors (1).

202121191 is an equidigital number, since it uses as much as digits as its factorization.

202121191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 202121191 is about 14216.9332487706. The cubic root of 202121191 is about 586.8637479578.

Adding to 202121191 its reverse (191121202), we get a palindrome (393242393).

The spelling of 202121191 in words is "two hundred two million, one hundred twenty-one thousand, one hundred ninety-one".