128391823 has 8 divisors (see below), whose sum is σ = 146810880. Its totient is φ = 109992120.

The previous prime is 128391821. The next prime is 128391829. The reversal of 128391823 is 328193821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128391823 - 2¹ = 128391821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128391821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14598 + ... + 21676.

It is an arithmetic number, because the mean of its divisors is an integer number (18351360).

Almost surely, 2^128391823 is an apocalyptic number.

128391823 is a deficient number, since it is larger than the sum of its proper divisors (18419057).

128391823 is an equidigital number, since it uses as much as digits as its factorization.

128391823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9677.

The product of its digits is 20736, while the sum is 37.

The square root of 128391823 is about 11331.0115611979. The cubic root of 128391823 is about 504.4821316009.

The spelling of 128391823 in words is "one hundred twenty-eight million, three hundred ninety-one thousand, eight hundred twenty-three".