1276891138 has 8 divisors (see below), whose sum is σ = 1998612288. Its totient is φ = 610687044.

The previous prime is 1276891081. The next prime is 1276891139. The reversal of 1276891138 is 8311986721.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (46), and also a Moran number because the ratio is a prime number: 27758503 = 1276891138 / (1 + 2 + 7 + 6 + 8 + 9 + 1 + 1 + 3 + 8).

It is not an unprimeable number, because it can be changed into a prime (1276891139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13879206 + ... + 13879297.

It is an arithmetic number, because the mean of its divisors is an integer number (249826536).

Almost surely, 2^1276891138 is an apocalyptic number.

1276891138 is a deficient number, since it is larger than the sum of its proper divisors (721721150).

1276891138 is a wasteful number, since it uses less digits than its factorization.

1276891138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27758528.

The product of its digits is 145152, while the sum is 46.

The square root of 1276891138 is about 35733.6135592246. The cubic root of 1276891138 is about 1084.8872975732.

The spelling of 1276891138 in words is "one billion, two hundred seventy-six million, eight hundred ninety-one thousand, one hundred thirty-eight".