1277541989 has 2 divisors, whose sum is σ = 1277541990. Its totient is φ = 1277541988.

The previous prime is 1277541977. The next prime is 1277542039. The reversal of 1277541989 is 9891457721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1099452964 + 178089025 = 33158^2 + 13345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1277541989 - 2⁴ = 1277541973 is a prime.

It is a super-2 number, since 2×1277541989² = 3264227067316152242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1277541989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1277541289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638770994 + 638770995.

It is an arithmetic number, because the mean of its divisors is an integer number (638770995).

Almost surely, 2^1277541989 is an apocalyptic number.

It is an amenable number.

1277541989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1277541989 is an equidigital number, since it uses as much as digits as its factorization.

1277541989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1270080, while the sum is 53.

The square root of 1277541989 is about 35742.7193845124. The cubic root of 1277541989 is about 1085.0715941629.

The spelling of 1277541989 in words is "one billion, two hundred seventy-seven million, five hundred forty-one thousand, nine hundred eighty-nine".