128126817 has 36 divisors (see below), whose sum is σ = 231858900. Its totient is φ = 67580352.

The previous prime is 128126809. The next prime is 128126821. The reversal of 128126817 is 718621821.

It can be written as a sum of positive squares in 2 ways, for example, as 19633761 + 108493056 = 4431^2 + 10416^2 .

It is not a de Polignac number, because 128126817 - 2³ = 128126809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128126827) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5442 + ... + 16907.

It is an arithmetic number, because the mean of its divisors is an integer number (6440525).

Almost surely, 2^128126817 is an apocalyptic number.

It is an amenable number.

128126817 is a deficient number, since it is larger than the sum of its proper divisors (103732083).

128126817 is a wasteful number, since it uses less digits than its factorization.

128126817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22382 (or 22372 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 128126817 is about 11319.3116840204. The cubic root of 128126817 is about 504.1348019051.

The spelling of 128126817 in words is "one hundred twenty-eight million, one hundred twenty-six thousand, eight hundred seventeen".