128421199872 has 384 divisors, whose sum is σ = 440234121600. Its totient is φ = 36691771392.

The previous prime is 128421199847. The next prime is 128421199889. The reversal of 128421199872 is 278991124821.

128421199872 is a `hidden beast` number, since 1 + 28 + 421 + 199 + 8 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

Its product of digits (1161216) is a multiple of the sum of its prime divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18345885693 + ... + 18345885699.

It is an arithmetic number, because the mean of its divisors is an integer number (1146443025).

Almost surely, 2^128421199872 is an apocalyptic number.

128421199872 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 128421199872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220117060800).

128421199872 is an abundant number, since it is smaller than the sum of its proper divisors (311812921728).

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

128421199872 is an frugal number, since it uses more digits than its factorization.

128421199872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 12 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

128421199872 divided by its product of digits (1161216) gives a cube (110592 = 48³).

The spelling of 128421199872 in words is "one hundred twenty-eight billion, four hundred twenty-one million, one hundred ninety-nine thousand, eight hundred seventy-two".