1277942749 has 2 divisors, whose sum is σ = 1277942750. Its totient is φ = 1277942748.

The previous prime is 1277942719. The next prime is 1277942821. The reversal of 1277942749 is 9472497721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1218498649 + 59444100 = 34907^2 + 7710^2 .

It is a cyclic number.

It is not a de Polignac number, because 1277942749 - 2²⁷ = 1143725021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1277942696 and 1277942705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1277942719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638971374 + 638971375.

It is an arithmetic number, because the mean of its divisors is an integer number (638971375).

Almost surely, 2^1277942749 is an apocalyptic number.

It is an amenable number.

1277942749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1277942749 is an equidigital number, since it uses as much as digits as its factorization.

1277942749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 52.

The square root of 1277942749 is about 35748.3251216053. The cubic root of 1277942749 is about 1085.1850432271.

The spelling of 1277942749 in words is "one billion, two hundred seventy-seven million, nine hundred forty-two thousand, seven hundred forty-nine".