1221221100977 has 2 divisors, whose sum is σ = 1221221100978. Its totient is φ = 1221221100976.

The previous prime is 1221221100947. The next prime is 1221221101039. The reversal of 1221221100977 is 7790011221221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 861881997376 + 359339103601 = 928376^2 + 599449^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221221100977 - 2²⁸ = 1220952665521 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221221100907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610550488 + 610610550489.

It is an arithmetic number, because the mean of its divisors is an integer number (610610550489).

Almost surely, 2^{1221221100977} is an apocalyptic number.

It is an amenable number.

1221221100977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221221100977 is an equidigital number, since it uses as much as digits as its factorization.

1221221100977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 35.

The spelling of 1221221100977 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred thousand, nine hundred seventy-seven".