201212021 has 2 divisors, whose sum is σ = 201212022. Its totient is φ = 201212020.

The previous prime is 201211999. The next prime is 201212023. The reversal of 201212021 is 120212102.

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., 155500900 + 45711121 = 12470^2 + 6761^2 .

It is a cyclic number.

It is not a de Polignac number, because 201212021 - 2¹⁴ = 201195637 is a prime.

Together with 201212023, 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 = 201211993 and 201212011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201212023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100606010 + 100606011.

It is an arithmetic number, because the mean of its divisors is an integer number (100606011).

Almost surely, 2^201212021 is an apocalyptic number.

It is an amenable number.

201212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

201212021 is an equidigital number, since it uses as much as digits as its factorization.

201212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 201212021 is about 14184.9223120890. The cubic root of 201212021 is about 585.9824929636.

Adding to 201212021 its reverse (120212102), we get a palindrome (321424123).

The spelling of 201212021 in words is "two hundred one million, two hundred twelve thousand, twenty-one".