1221201021011 has 2 divisors, whose sum is σ = 1221201021012. Its totient is φ = 1221201021010.

The previous prime is 1221201020989. The next prime is 1221201021023. The reversal of 1221201021011 is 1101201021221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221201021011 - 2¹⁸ = 1221200758867 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221201024011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610600510505 + 610600510506.

It is an arithmetic number, because the mean of its divisors is an integer number (610600510506).

Almost surely, 2^{1221201021011} is an apocalyptic number.

1221201021011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221201021011 is an equidigital number, since it uses as much as digits as its factorization.

1221201021011 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 14.

Adding to 1221201021011 its reverse (1101201021221), we get a palindrome (2322402042232).

The spelling of 1221201021011 in words is "one trillion, two hundred twenty-one billion, two hundred one million, twenty-one thousand, eleven".