2019202121 has 2 divisors, whose sum is σ = 2019202122. Its totient is φ = 2019202120.

The previous prime is 2019202117. The next prime is 2019202123. The reversal of 2019202121 is 1212029102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1914937600 + 104264521 = 43760^2 + 10211^2 .

It is a cyclic number.

It is not a de Polignac number, because 2019202121 - 2² = 2019202117 is a prime.

Together with 2019202123, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 2019202093 and 2019202102.

It is not a weakly prime, because it can be changed into another prime (2019202123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1009601060 + 1009601061.

It is an arithmetic number, because the mean of its divisors is an integer number (1009601061).

Almost surely, 2^2019202121 is an apocalyptic number.

It is an amenable number.

2019202121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2019202121 is an equidigital number, since it uses as much as digits as its factorization.

2019202121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 2019202121 is about 44935.5329444305. The cubic root of 2019202121 is about 1263.9404065883.

It can be divided in two parts, 2019202 and 121, that multiplied together give a palindrome (244323442).

The spelling of 2019202121 in words is "two billion, nineteen million, two hundred two thousand, one hundred twenty-one".