1276761057721 has 2 divisors, whose sum is σ = 1276761057722. Its totient is φ = 1276761057720.

The previous prime is 1276761057713. The next prime is 1276761057731. The reversal of 1276761057721 is 1277501676721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 968029693225 + 308731364496 = 983885^2 + 555636^2 .

It is a cyclic number.

It is not a de Polignac number, because 1276761057721 - 2³ = 1276761057713 is a prime.

It is not a weakly prime, because it can be changed into another prime (1276761057731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638380528860 + 638380528861.

It is an arithmetic number, because the mean of its divisors is an integer number (638380528861).

Almost surely, 2^{1276761057721} is an apocalyptic number.

It is an amenable number.

1276761057721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1276761057721 is an equidigital number, since it uses as much as digits as its factorization.

1276761057721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728720, while the sum is 52.

The spelling of 1276761057721 in words is "one trillion, two hundred seventy-six billion, seven hundred sixty-one million, fifty-seven thousand, seven hundred twenty-one".