1221122020177 has 2 divisors, whose sum is σ = 1221122020178. Its totient is φ = 1221122020176.

The previous prime is 1221122020169. The next prime is 1221122020249. The reversal of 1221122020177 is 7710202211221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1208172490561 + 12949529616 = 1099169^2 + 113796^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221122020177 - 2³ = 1221122020169 is a prime.

It is a super-2 number, since 2×1221122020177² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221122020127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610561010088 + 610561010089.

It is an arithmetic number, because the mean of its divisors is an integer number (610561010089).

Almost surely, 2^{1221122020177} is an apocalyptic number.

It is an amenable number.

1221122020177 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221122020177 is an equidigital number, since it uses as much as digits as its factorization.

1221122020177 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1568, while the sum is 28.

Adding to 1221122020177 its reverse (7710202211221), we get a palindrome (8931324231398).

The spelling of 1221122020177 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, twenty thousand, one hundred seventy-seven".