2001212021 has 2 divisors, whose sum is σ = 2001212022. Its totient is φ = 2001212020.

The previous prime is 2001211981. The next prime is 2001212047. The reversal of 2001212021 is 1202121002.

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., 1551178225 + 450033796 = 39385^2 + 21214^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001212021 - 2²² = 1997017717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001211993 and 2001212011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001212921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000606010 + 1000606011.

It is an arithmetic number, because the mean of its divisors is an integer number (1000606011).

Almost surely, 2^2001212021 is an apocalyptic number.

It is an amenable number.

2001212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001212021 is an equidigital number, since it uses as much as digits as its factorization.

2001212021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2001212021 is about 44734.9083043656. The cubic root of 2001212021 is about 1260.1755069624.

Adding to 2001212021 its reverse (1202121002), we get a palindrome (3203333023).

The spelling of 2001212021 in words is "two billion, one million, two hundred twelve thousand, twenty-one".