1265761878 has 16 divisors (see below), whose sum is σ = 2531974656. Its totient is φ = 421845480.

The previous prime is 1265761873. The next prime is 1265761907. The reversal of 1265761878 is 8781675621.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1265761878.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265761873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25875 + ... + 56577.

It is an arithmetic number, because the mean of its divisors is an integer number (158248416).

Almost surely, 2^1265761878 is an apocalyptic number.

1265761878 is an abundant number, since it is smaller than the sum of its proper divisors (1266212778).

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

1265761878 is a wasteful number, since it uses less digits than its factorization.

1265761878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37579.

The product of its digits is 1128960, while the sum is 51.

The square root of 1265761878 is about 35577.5473859568. The cubic root of 1265761878 is about 1081.7261713346.

The spelling of 1265761878 in words is "one billion, two hundred sixty-five million, seven hundred sixty-one thousand, eight hundred seventy-eight".