1276262161 has 4 divisors (see below), whose sum is σ = 1281006900. Its totient is φ = 1271517424.

The previous prime is 1276262153. The next prime is 1276262171. The reversal of 1276262161 is 1612626721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 648007936 + 628254225 = 25456^2 + 25065^2 .

It is a cyclic number.

It is not a de Polignac number, because 1276262161 - 2³ = 1276262153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1276262171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2371966 + ... + 2372503.

It is an arithmetic number, because the mean of its divisors is an integer number (320251725).

Almost surely, 2^1276262161 is an apocalyptic number.

It is an amenable number.

1276262161 is a deficient number, since it is larger than the sum of its proper divisors (4744739).

1276262161 is an equidigital number, since it uses as much as digits as its factorization.

1276262161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4744738.

The product of its digits is 12096, while the sum is 34.

The square root of 1276262161 is about 35724.8115600349. The cubic root of 1276262161 is about 1084.7091353662.

Adding to 1276262161 its reverse (1612626721), we get a palindrome (2888888882).

The spelling of 1276262161 in words is "one billion, two hundred seventy-six million, two hundred sixty-two thousand, one hundred sixty-one".