1296277885765 has 4 divisors (see below), whose sum is σ = 1555533462924. Its totient is φ = 1037022308608.

The previous prime is 1296277885741. The next prime is 1296277885811. The reversal of 1296277885765 is 5675887726921.

It is a happy number.

It is a Cunningham number, because it is equal to 1138542²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 466661131876 + 829616753889 = 683126^2 + 910833^2 .

It is a cyclic number.

It is not a de Polignac number, because 1296277885765 - 2¹¹ = 1296277883717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129627788572 + ... + 129627788581.

It is an arithmetic number, because the mean of its divisors is an integer number (388883365731).

Almost surely, 2^{1296277885765} is an apocalyptic number.

It is an amenable number.

1296277885765 is a deficient number, since it is larger than the sum of its proper divisors (259255577159).

1296277885765 is an equidigital number, since it uses as much as digits as its factorization.

1296277885765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259255577158.

The product of its digits is 711244800, while the sum is 73.

The spelling of 1296277885765 in words is "one trillion, two hundred ninety-six billion, two hundred seventy-seven million, eight hundred eighty-five thousand, seven hundred sixty-five".