1265781828 has 24 divisors (see below), whose sum is σ = 3009218688. Its totient is φ = 413966176.

The previous prime is 1265781827. The next prime is 1265781833. The reversal of 1265781828 is 8281875621.

It is not an unprimeable number, because it can be changed into a prime (1265781827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 994476 + ... + 995747.

It is an arithmetic number, because the mean of its divisors is an integer number (125384112).

Almost surely, 2^1265781828 is an apocalyptic number.

It is an amenable number.

1265781828 is an abundant number, since it is smaller than the sum of its proper divisors (1743436860).

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

1265781828 is a wasteful number, since it uses less digits than its factorization.

1265781828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1990283 (or 1990281 counting only the distinct ones).

The product of its digits is 430080, while the sum is 48.

The square root of 1265781828 is about 35577.8277583104. The cubic root of 1265781828 is about 1081.7318544266.

The spelling of 1265781828 in words is "one billion, two hundred sixty-five million, seven hundred eighty-one thousand, eight hundred twenty-eight".