1212130021 has 2 divisors, whose sum is σ = 1212130022. Its totient is φ = 1212130020.

The previous prime is 1212130019. The next prime is 1212130057. The reversal of 1212130021 is 1200312121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1212084225 + 45796 = 34815^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212130021 - 2¹ = 1212130019 is a prime.

Together with 1212130019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1212129983 and 1212130010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212130421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606065010 + 606065011.

It is an arithmetic number, because the mean of its divisors is an integer number (606065011).

Almost surely, 2^1212130021 is an apocalyptic number.

It is an amenable number.

1212130021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212130021 is an equidigital number, since it uses as much as digits as its factorization.

1212130021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1212130021 is about 34815.6576987998. The cubic root of 1212130021 is about 1066.2271471220.

Adding to 1212130021 its reverse (1200312121), we get a palindrome (2412442142).

The spelling of 1212130021 in words is "one billion, two hundred twelve million, one hundred thirty thousand, twenty-one".