1211012021 has 2 divisors, whose sum is σ = 1211012022. Its totient is φ = 1211012020.

The previous prime is 1211011951. The next prime is 1211012029. The reversal of 1211012021 is 1202101121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 974313796 + 236698225 = 31214^2 + 15385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211012021 - 2¹⁴ = 1210995637 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 = 1211011993 and 1211012011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211012029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605506010 + 605506011.

It is an arithmetic number, because the mean of its divisors is an integer number (605506011).

Almost surely, 2^1211012021 is an apocalyptic number.

It is an amenable number.

1211012021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211012021 is an equidigital number, since it uses as much as digits as its factorization.

1211012021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1211012021 is about 34799.5980005517. The cubic root of 1211012021 is about 1065.8992371320.

Adding to 1211012021 its reverse (1202101121), we get a palindrome (2413113142).

The spelling of 1211012021 in words is "one billion, two hundred eleven million, twelve thousand, twenty-one".