128947957 has 4 divisors (see below), whose sum is σ = 129130540. Its totient is φ = 128765376.

The previous prime is 128947943. The next prime is 128947963. The reversal of 128947957 is 759749821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34586161 + 94361796 = 5881^2 + 9714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128947957 is a prime.

It is a super-2 number, since 2×128947957² = 33255151228947698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128947967) 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 3 ways as a sum of consecutive naturals, for example, 90228 + ... + 91645.

It is an arithmetic number, because the mean of its divisors is an integer number (32282635).

Almost surely, 2^128947957 is an apocalyptic number.

It is an amenable number.

128947957 is a deficient number, since it is larger than the sum of its proper divisors (182583).

128947957 is an equidigital number, since it uses as much as digits as its factorization.

128947957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182582.

The product of its digits is 1270080, while the sum is 52.

The square root of 128947957 is about 11355.5253951546. The cubic root of 128947957 is about 505.2094768641.

The spelling of 128947957 in words is "one hundred twenty-eight million, nine hundred forty-seven thousand, nine hundred fifty-seven".