123432128821 has 8 divisors (see below), whose sum is σ = 124511004288. Its totient is φ = 122355324000.

The previous prime is 123432128783. The next prime is 123432128843. The reversal of 123432128821 is 128821234321.

It is the 143430-th star number.

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

It is a 4-Lehmer number, since φ(123432128821) divides (123432128821-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 123432128821 - 2³⁵ = 89072390453 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 (123432128851) 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, 397800 + ... + 636481.

It is an arithmetic number, because the mean of its divisors is an integer number (15563875536).

Almost surely, 2^123432128821 is an apocalyptic number.

It is an amenable number.

123432128821 is a deficient number, since it is larger than the sum of its proper divisors (1078875467).

123432128821 is a wasteful number, since it uses less digits than its factorization.

123432128821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1035323.

The product of its digits is 36864, while the sum is 37.

The spelling of 123432128821 in words is "one hundred twenty-three billion, four hundred thirty-two million, one hundred twenty-eight thousand, eight hundred twenty-one".