128837857 has 4 divisors (see below), whose sum is σ = 131579136. Its totient is φ = 126096580.

The previous prime is 128837843. The next prime is 128837869. The reversal of 128837857 is 758738821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 758738821 = 3527 ⋅215123.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128837857 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128837857.

It is not an unprimeable number, because it can be changed into a prime (128837837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1370569 + ... + 1370662.

It is an arithmetic number, because the mean of its divisors is an integer number (32894784).

Almost surely, 2^128837857 is an apocalyptic number.

It is an amenable number.

128837857 is a deficient number, since it is larger than the sum of its proper divisors (2741279).

128837857 is an equidigital number, since it uses as much as digits as its factorization.

128837857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2741278.

The product of its digits is 752640, while the sum is 49.

The square root of 128837857 is about 11350.6764996629. The cubic root of 128837857 is about 505.0656477739.

The spelling of 128837857 in words is "one hundred twenty-eight million, eight hundred thirty-seven thousand, eight hundred fifty-seven".