1277615772491 has 2 divisors, whose sum is σ = 1277615772492. Its totient is φ = 1277615772490.

The previous prime is 1277615772479. The next prime is 1277615772539. The reversal of 1277615772491 is 1942775167721.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1277615772491 - 2²⁶ = 1277548663627 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1277615772491.

It is not a weakly prime, because it can be changed into another prime (1277615772421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638807886245 + 638807886246.

It is an arithmetic number, because the mean of its divisors is an integer number (638807886246).

Almost surely, 2^{1277615772491} is an apocalyptic number.

1277615772491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1277615772491 is an equidigital number, since it uses as much as digits as its factorization.

1277615772491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10372320, while the sum is 59.

The spelling of 1277615772491 in words is "one trillion, two hundred seventy-seven billion, six hundred fifteen million, seven hundred seventy-two thousand, four hundred ninety-one".