1212221891057 has 2 divisors, whose sum is σ = 1212221891058. Its totient is φ = 1212221891056.

The previous prime is 1212221891029. The next prime is 1212221891119. The reversal of 1212221891057 is 7501981222121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 692675017441 + 519546873616 = 832271^2 + 720796^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212221891057 - 2³² = 1207926923761 is a prime.

It is not a weakly prime, because it can be changed into another prime (1212221491057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606110945528 + 606110945529.

It is an arithmetic number, because the mean of its divisors is an integer number (606110945529).

Almost surely, 2^{1212221891057} is an apocalyptic number.

It is an amenable number.

1212221891057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212221891057 is an equidigital number, since it uses as much as digits as its factorization.

1212221891057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 41.

The spelling of 1212221891057 in words is "one trillion, two hundred twelve billion, two hundred twenty-one million, eight hundred ninety-one thousand, fifty-seven".