1275036221681 has 2 divisors, whose sum is σ = 1275036221682. Its totient is φ = 1275036221680.

The previous prime is 1275036221663. The next prime is 1275036221717. The reversal of 1275036221681 is 1861226305721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1178961640000 + 96074581681 = 1085800^2 + 309959^2 .

It is a cyclic number.

It is not a de Polignac number, because 1275036221681 - 2⁶ = 1275036221617 is a prime.

It is a super-2 number, since 2×1275036221681² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1275036221581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637518110840 + 637518110841.

It is an arithmetic number, because the mean of its divisors is an integer number (637518110841).

Almost surely, 2^{1275036221681} is an apocalyptic number.

It is an amenable number.

1275036221681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275036221681 is an equidigital number, since it uses as much as digits as its factorization.

1275036221681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 1275036221681 in words is "one trillion, two hundred seventy-five billion, thirty-six million, two hundred twenty-one thousand, six hundred eighty-one".