1210121021 has 2 divisors, whose sum is σ = 1210121022. Its totient is φ = 1210121020.

The previous prime is 1210120999. The next prime is 1210121051. The reversal of 1210121021 is 1201210121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1210065796 + 55225 = 34786^2 + 235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210121021 - 2⁶ = 1210120957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1210120993 and 1210121011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1210121051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605060510 + 605060511.

It is an arithmetic number, because the mean of its divisors is an integer number (605060511).

Almost surely, 2^1210121021 is an apocalyptic number.

It is an amenable number.

1210121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1210121021 is an equidigital number, since it uses as much as digits as its factorization.

1210121021 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 1210121021 is about 34786.7937729248. The cubic root of 1210121021 is about 1065.6377618215.

Adding to 1210121021 its reverse (1201210121), we get a palindrome (2411331142).

The spelling of 1210121021 in words is "one billion, two hundred ten million, one hundred twenty-one thousand, twenty-one".