128440979100 has 576 divisors, whose sum is σ = 487048826880. Its totient is φ = 28785818880.

The previous prime is 128440979011. The next prime is 128440979101. The reversal of 128440979100 is 1979044821.

It is a happy number.

128440979100 is a `hidden beast` number, since 12 + 8 + 440 + 97 + 9 + 100 = 666.

It is a super-2 number, since 2×128440979100² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128440979101) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 81136909 + ... + 81138491.

It is an arithmetic number, because the mean of its divisors is an integer number (845570880).

Almost surely, 2^128440979100 is an apocalyptic number.

128440979100 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 128440979100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243524413440).

128440979100 is an abundant number, since it is smaller than the sum of its proper divisors (358607847780).

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

128440979100 is a wasteful number, since it uses less digits than its factorization.

128440979100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678 (or 1653 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 128440979100 in words is "one hundred twenty-eight billion, four hundred forty million, nine hundred seventy-nine thousand, one hundred".