128643523 has 4 divisors (see below), whose sum is σ = 128670480. Its totient is φ = 128616568.

The previous prime is 128643497. The next prime is 128643533. The reversal of 128643523 is 325346821.

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 128643523 - 2⁵ = 128643491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128643533) 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, 4183 + ... + 16576.

It is an arithmetic number, because the mean of its divisors is an integer number (32167620).

Almost surely, 2^128643523 is an apocalyptic number.

128643523 is a deficient number, since it is larger than the sum of its proper divisors (26957).

128643523 is an equidigital number, since it uses as much as digits as its factorization.

128643523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26956.

The product of its digits is 34560, while the sum is 34.

The square root of 128643523 is about 11342.1128102307. The cubic root of 128643523 is about 504.8115795455.

The spelling of 128643523 in words is "one hundred twenty-eight million, six hundred forty-three thousand, five hundred twenty-three".