1221036301721 has 2 divisors, whose sum is σ = 1221036301722. Its totient is φ = 1221036301720.

The previous prime is 1221036301691. The next prime is 1221036301741. The reversal of 1221036301721 is 1271036301221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 667797861721 + 553238440000 = 817189^2 + 743800^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221036301721 - 2¹⁰ = 1221036300697 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221036301741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610518150860 + 610518150861.

It is an arithmetic number, because the mean of its divisors is an integer number (610518150861).

Almost surely, 2^{1221036301721} is an apocalyptic number.

It is an amenable number.

1221036301721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221036301721 is an equidigital number, since it uses as much as digits as its factorization.

1221036301721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The spelling of 1221036301721 in words is "one trillion, two hundred twenty-one billion, thirty-six million, three hundred one thousand, seven hundred twenty-one".