1277716261 has 2 divisors, whose sum is σ = 1277716262. Its totient is φ = 1277716260.

The previous prime is 1277716189. The next prime is 1277716283. The reversal of 1277716261 is 1626177721.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1277705025 + 11236 = 35745^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 1277716261 - 2¹⁷ = 1277585189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1277716361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638858130 + 638858131.

It is an arithmetic number, because the mean of its divisors is an integer number (638858131).

Almost surely, 2^1277716261 is an apocalyptic number.

It is an amenable number.

1277716261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1277716261 is an equidigital number, since it uses as much as digits as its factorization.

1277716261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 40.

The square root of 1277716261 is about 35745.1571684893. The cubic root of 1277716261 is about 1085.1209308320.

The spelling of 1277716261 in words is "one billion, two hundred seventy-seven million, seven hundred sixteen thousand, two hundred sixty-one".