1277949643 has 2 divisors, whose sum is σ = 1277949644. Its totient is φ = 1277949642.

The previous prime is 1277949601. The next prime is 1277949649. The reversal of 1277949643 is 3469497721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1277949643 - 2²¹ = 1275852491 is a prime.

It is not a weakly prime, because it can be changed into another prime (1277949649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638974821 + 638974822.

It is an arithmetic number, because the mean of its divisors is an integer number (638974822).

Almost surely, 2^1277949643 is an apocalyptic number.

1277949643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1277949643 is an equidigital number, since it uses as much as digits as its factorization.

1277949643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 52.

The square root of 1277949643 is about 35748.4215455732. The cubic root of 1277949643 is about 1085.1869946062.

The spelling of 1277949643 in words is "one billion, two hundred seventy-seven million, nine hundred forty-nine thousand, six hundred forty-three".