1296655681 has 2 divisors, whose sum is σ = 1296655682. Its totient is φ = 1296655680.

The previous prime is 1296655667. The next prime is 1296655727. The reversal of 1296655681 is 1865566921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 680375056 + 616280625 = 26084^2 + 24825^2 .

It is an emirp because it is prime and its reverse (1865566921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1296655681 - 2¹³ = 1296647489 is a prime.

It is a super-2 number, since 2×1296655681² = 3362631910139147522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1296655651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 648327840 + 648327841.

It is an arithmetic number, because the mean of its divisors is an integer number (648327841).

Almost surely, 2^1296655681 is an apocalyptic number.

It is an amenable number.

1296655681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1296655681 is an equidigital number, since it uses as much as digits as its factorization.

1296655681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 777600, while the sum is 49.

The square root of 1296655681 is about 36009.1055290186. The cubic root of 1296655681 is about 1090.4561906645.

The spelling of 1296655681 in words is "one billion, two hundred ninety-six million, six hundred fifty-five thousand, six hundred eighty-one".