1276545204649 has 27 divisors (see below), whose sum is σ = 1519573897317. Its totient is φ = 1071091164000.

The previous prime is 1276545204563. The next prime is 1276545204667. The reversal of 1276545204649 is 9464025456721.

The square root of 1276545204649 is 1129843.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 49838330025 + 1226706874624 = 223245^2 + 1107568^2 .

It is not a de Polignac number, because 1276545204649 - 2¹¹ = 1276545202601 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1276545204649.

It is not an unprimeable number, because it can be changed into a prime (1276545202649) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 161563599 + ... + 161571499.

Almost surely, 2^{1276545204649} is an apocalyptic number.

1276545204649 is the 1129843-rd square number.

1276545204649 is the 564922-nd centered octagonal number.

It is an amenable number.

1276545204649 is a deficient number, since it is larger than the sum of its proper divisors (243028692668).

1276545204649 is an frugal number, since it uses more digits than its factorization.

1276545204649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15850 (or 7925 counting only the distinct ones).

The product of its (nonzero) digits is 14515200, while the sum is 55.

The spelling of 1276545204649 in words is "one trillion, two hundred seventy-six billion, five hundred forty-five million, two hundred four thousand, six hundred forty-nine".