1221020077 has 2 divisors, whose sum is σ = 1221020078. Its totient is φ = 1221020076.

The previous prime is 1221020069. The next prime is 1221020093. The reversal of 1221020077 is 7700201221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1123188196 + 97831881 = 33514^2 + 9891^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221020077 - 2³ = 1221020069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221020677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610510038 + 610510039.

It is an arithmetic number, because the mean of its divisors is an integer number (610510039).

Almost surely, 2^1221020077 is an apocalyptic number.

It is an amenable number.

1221020077 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221020077 is an equidigital number, since it uses as much as digits as its factorization.

1221020077 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.

The square root of 1221020077 is about 34943.0977018352. The cubic root of 1221020077 is about 1068.8274566390.

Adding to 1221020077 its reverse (7700201221), we get a palindrome (8921221298).

The spelling of 1221020077 in words is "one billion, two hundred twenty-one million, twenty thousand, seventy-seven".