1221000020077 has 2 divisors, whose sum is σ = 1221000020078. Its totient is φ = 1221000020076.

The previous prime is 1221000020059. The next prime is 1221000020111. The reversal of 1221000020077 is 7700200001221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1197402759081 + 23597260996 = 1094259^2 + 153614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221000020077 - 2¹⁹ = 1220999495789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221000080077) 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, 610500010038 + 610500010039.

It is an arithmetic number, because the mean of its divisors is an integer number (610500010039).

Almost surely, 2^{1221000020077} is an apocalyptic number.

It is an amenable number.

1221000020077 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221000020077 is an equidigital number, since it uses as much as digits as its factorization.

1221000020077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 392, while the sum is 22.

Adding to 1221000020077 its reverse (7700200001221), we get a palindrome (8921200021298).

The spelling of 1221000020077 in words is "one trillion, two hundred twenty-one billion, twenty thousand, seventy-seven".