1277821128 has 16 divisors (see below), whose sum is σ = 3194552880. Its totient is φ = 425940368.

The previous prime is 1277821123. The next prime is 1277821141. The reversal of 1277821128 is 8211287721.

It is not an unprimeable number, because it can be changed into a prime (1277821123) 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, 26621250 + ... + 26621297.

It is an arithmetic number, because the mean of its divisors is an integer number (199659555).

Almost surely, 2^1277821128 is an apocalyptic number.

It is an amenable number.

1277821128 is an abundant number, since it is smaller than the sum of its proper divisors (1916731752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1277821128 is a wasteful number, since it uses less digits than its factorization.

1277821128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53242556 (or 53242552 counting only the distinct ones).

The product of its digits is 25088, while the sum is 39.

The square root of 1277821128 is about 35746.6240084291. The cubic root of 1277821128 is about 1085.1506166778.

The spelling of 1277821128 in words is "one billion, two hundred seventy-seven million, eight hundred twenty-one thousand, one hundred twenty-eight".