128340829 has 4 divisors (see below), whose sum is σ = 129540384. Its totient is φ = 127141276.

The previous prime is 128340811. The next prime is 128340833. The reversal of 128340829 is 928043821.

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: 928043821 = 17 ⋅54590813.

It is a cyclic number.

It is not a de Polignac number, because 128340829 - 2²⁵ = 94786397 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 (128340809) 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, 599617 + ... + 599830.

It is an arithmetic number, because the mean of its divisors is an integer number (32385096).

Almost surely, 2^128340829 is an apocalyptic number.

It is an amenable number.

128340829 is a deficient number, since it is larger than the sum of its proper divisors (1199555).

128340829 is a wasteful number, since it uses less digits than its factorization.

128340829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199554.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 128340829 is about 11328.7611414488. The cubic root of 128340829 is about 504.4153335556.

The spelling of 128340829 in words is "one hundred twenty-eight million, three hundred forty thousand, eight hundred twenty-nine".