128579940 has 96 divisors (see below), whose sum is σ = 412984320. Its totient is φ = 33177600.

The previous prime is 128579923. The next prime is 128579951. The reversal of 128579940 is 49975821.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12900 + ... + 20580.

It is an arithmetic number, because the mean of its divisors is an integer number (4301920).

Almost surely, 2^128579940 is an apocalyptic number.

128579940 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 128579940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206492160).

128579940 is an abundant number, since it is smaller than the sum of its proper divisors (284404380).

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

128579940 is a wasteful number, since it uses less digits than its factorization.

128579940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7730 (or 7722 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 128579940 is about 11339.3095027872. The cubic root of 128579940 is about 504.7283969038.

It can be divided in two parts, 1285 and 79940, that added together give a square (81225 = 285²).

The spelling of 128579940 in words is "one hundred twenty-eight million, five hundred seventy-nine thousand, nine hundred forty".