1261637912653 has 2 divisors, whose sum is σ = 1261637912654. Its totient is φ = 1261637912652.

The previous prime is 1261637912629. The next prime is 1261637912681. The reversal of 1261637912653 is 3562197361621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1238586474724 + 23051437929 = 1112918^2 + 151827^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261637912653 - 2²¹ = 1261635815501 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1261637912653.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261637912153) 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, 630818956326 + 630818956327.

It is an arithmetic number, because the mean of its divisors is an integer number (630818956327).

Almost surely, 2^{1261637912653} is an apocalyptic number.

It is an amenable number.

1261637912653 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261637912653 is an equidigital number, since it uses as much as digits as its factorization.

1261637912653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2449440, while the sum is 52.

The spelling of 1261637912653 in words is "one trillion, two hundred sixty-one billion, six hundred thirty-seven million, nine hundred twelve thousand, six hundred fifty-three".