1221212210077 has 2 divisors, whose sum is σ = 1221212210078. Its totient is φ = 1221212210076.

The previous prime is 1221212210011. The next prime is 1221212210149. The reversal of 1221212210077 is 7700122121221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1172999468601 + 48212741476 = 1083051^2 + 219574^2 .

It is an emirp because it is prime and its reverse (7700122121221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221212210077 - 2⁷ = 1221212209949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221212210177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610606105038 + 610606105039.

It is an arithmetic number, because the mean of its divisors is an integer number (610606105039).

Almost surely, 2^{1221212210077} is an apocalyptic number.

It is an amenable number.

1221212210077 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221212210077 is an equidigital number, since it uses as much as digits as its factorization.

1221212210077 is an evil number, because the sum of its binary digits is even.

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

Adding to 1221212210077 its reverse (7700122121221), we get a palindrome (8921334331298).

The spelling of 1221212210077 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, seventy-seven".