128121221592 has 576 divisors, whose sum is σ = 453833452800. Its totient is φ = 32328253440.

The previous prime is 128121221521. The next prime is 128121221597. The reversal of 128121221592 is 295122121821.

128121221592 is a `hidden beast` number, since 1 + 28 + 1 + 21 + 2 + 21 + 592 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128121221597) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 137912584 + ... + 137913512.

It is an arithmetic number, because the mean of its divisors is an integer number (787905300).

Almost surely, 2^128121221592 is an apocalyptic number.

128121221592 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128121221592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226916726400).

128121221592 is an abundant number, since it is smaller than the sum of its proper divisors (325712231208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128121221592 is a wasteful number, since it uses less digits than its factorization.

128121221592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096 (or 1082 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The spelling of 128121221592 in words is "one hundred twenty-eight billion, one hundred twenty-one million, two hundred twenty-one thousand, five hundred ninety-two".