128261897280 has 672 divisors, whose sum is σ = 503973388800. Its totient is φ = 30680432640.

The previous prime is 128261897261. The next prime is 128261897293. The reversal of 128261897280 is 82798162821.

128261897280 is a `hidden beast` number, since 1 + 28 + 261 + 89 + 7 + 280 = 666.

It is a super-2 number, since 2×128261897280² (a number of 23 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 82588984 + ... + 82590536.

It is an arithmetic number, because the mean of its divisors is an integer number (749960400).

Almost surely, 2^128261897280 is an apocalyptic number.

128261897280 is a gapful number since it is divisible by the number (10) 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 128261897280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251986694400).

128261897280 is an abundant number, since it is smaller than the sum of its proper divisors (375711491520).

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

128261897280 is a wasteful number, since it uses less digits than its factorization.

128261897280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680 (or 1653 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 54.

The spelling of 128261897280 in words is "one hundred twenty-eight billion, two hundred sixty-one million, eight hundred ninety-seven thousand, two hundred eighty".