1221211121177 has 2 divisors, whose sum is σ = 1221211121178. Its totient is φ = 1221211121176.

The previous prime is 1221211121171. The next prime is 1221211121269. The reversal of 1221211121177 is 7711211121221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1058159911561 + 163051209616 = 1028669^2 + 403796^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221211121177 - 2²² = 1221206926873 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221211121171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610605560588 + 610605560589.

It is an arithmetic number, because the mean of its divisors is an integer number (610605560589).

Almost surely, 2^{1221211121177} is an apocalyptic number.

It is an amenable number.

1221211121177 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221211121177 is an equidigital number, since it uses as much as digits as its factorization.

1221211121177 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 784, while the sum is 29.

Adding to 1221211121177 its reverse (7711211121221), we get a palindrome (8932422242398).

The spelling of 1221211121177 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, one hundred seventy-seven".