128265813 has 12 divisors (see below), whose sum is σ = 199524780. Its totient is φ = 78932736.

The previous prime is 128265763. The next prime is 128265829. The reversal of 128265813 is 318562821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 47858724 + 80407089 = 6918^2 + 8967^2 .

It is not a de Polignac number, because 128265813 - 2²¹ = 126168661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128265013) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 548028 + ... + 548261.

It is an arithmetic number, because the mean of its divisors is an integer number (16627065).

Almost surely, 2^128265813 is an apocalyptic number.

128265813 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

128265813 is a deficient number, since it is larger than the sum of its proper divisors (71258967).

128265813 is a wasteful number, since it uses less digits than its factorization.

128265813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096308 (or 1096305 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 128265813 is about 11325.4497923924. The cubic root of 128265813 is about 504.3170364515.

The spelling of 128265813 in words is "one hundred twenty-eight million, two hundred sixty-five thousand, eight hundred thirteen".