128215823 has 8 divisors (see below), whose sum is σ = 135788928. Its totient is φ = 120809304.

The previous prime is 128215799. The next prime is 128215837. The reversal of 128215823 is 328512821.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 128215823 - 2¹⁶ = 128150287 is a prime.

It is a super-3 number, since 3×128215823³ (a number of 25 digits) contains 333 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 128215823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128215223) 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, 40061 + ... + 43142.

It is an arithmetic number, because the mean of its divisors is an integer number (16973616).

Almost surely, 2^128215823 is an apocalyptic number.

128215823 is a deficient number, since it is larger than the sum of its proper divisors (7573105).

128215823 is an equidigital number, since it uses as much as digits as its factorization.

128215823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83293.

The product of its digits is 7680, while the sum is 32.

The square root of 128215823 is about 11323.2426009514. The cubic root of 128215823 is about 504.2515108477.

The spelling of 128215823 in words is "one hundred twenty-eight million, two hundred fifteen thousand, eight hundred twenty-three".