1276220161 has 16 divisors (see below), whose sum is σ = 1326019968. Its totient is φ = 1227427200.

The previous prime is 1276220149. The next prime is 1276220191. The reversal of 1276220161 is 1610226721.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1276220161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1276220191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1169226 + ... + 1170316.

It is an arithmetic number, because the mean of its divisors is an integer number (82876248).

Almost surely, 2^1276220161 is an apocalyptic number.

It is an amenable number.

1276220161 is a deficient number, since it is larger than the sum of its proper divisors (49799807).

1276220161 is a wasteful number, since it uses less digits than its factorization.

1276220161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1512.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1276220161 is about 35724.2237284451. The cubic root of 1276220161 is about 1084.6972364829.

Adding to 1276220161 its reverse (1610226721), we get a palindrome (2886446882).

It can be divided in two parts, 12762 and 20161, that added together give a palindrome (32923).

The spelling of 1276220161 in words is "one billion, two hundred seventy-six million, two hundred twenty thousand, one hundred sixty-one".