1200212021 has 2 divisors, whose sum is σ = 1200212022. Its totient is φ = 1200212020.

The previous prime is 1200212017. The next prime is 1200212029. The reversal of 1200212021 is 1202120021.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 749116900 + 451095121 = 27370^2 + 21239^2 .

It is an emirp because it is prime and its reverse (1202120021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1200212021 - 2² = 1200212017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1200211993 and 1200212011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200212029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600106010 + 600106011.

It is an arithmetic number, because the mean of its divisors is an integer number (600106011).

Almost surely, 2^1200212021 is an apocalyptic number.

It is an amenable number.

1200212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200212021 is an equidigital number, since it uses as much as digits as its factorization.

1200212021 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 1200212021 is about 34644.0762757502. The cubic root of 1200212021 is about 1062.7211504783.

Adding to 1200212021 its reverse (1202120021), we get a palindrome (2402332042).

The spelling of 1200212021 in words is "one billion, two hundred million, two hundred twelve thousand, twenty-one".