128591843 has 4 divisors (see below), whose sum is σ = 130699968. Its totient is φ = 126483720.

The previous prime is 128591831. The next prime is 128591921. The reversal of 128591843 is 348195821.

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

It is a cyclic number.

It is not a de Polignac number, because 128591843 - 2⁶ = 128591779 is a prime.

It is a super-2 number, since 2×128591843² = 33071724172273298, which contains 22 as substring.

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 128591843.

It is not an unprimeable number, because it can be changed into a prime (128591803) 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, 1053971 + ... + 1054092.

It is an arithmetic number, because the mean of its divisors is an integer number (32674992).

Almost surely, 2^128591843 is an apocalyptic number.

128591843 is a deficient number, since it is larger than the sum of its proper divisors (2108125).

128591843 is an equidigital number, since it uses as much as digits as its factorization.

128591843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2108124.

The product of its digits is 69120, while the sum is 41.

The square root of 128591843 is about 11339.8343462328. The cubic root of 128591843 is about 504.7439711235.

The spelling of 128591843 in words is "one hundred twenty-eight million, five hundred ninety-one thousand, eight hundred forty-three".