128499840 has 192 divisors, whose sum is σ = 507274560. Its totient is φ = 29362176.

The previous prime is 128499823. The next prime is 128499857. The reversal of 128499840 is 48994821.

It is an interprime number because it is at equal distance from previous prime (128499823) and next prime (128499857).

It is a tau number, because it is divible by the number of its divisors (192).

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 23 ways as a sum of consecutive naturals, for example, 38727 + ... + 41913.

It is an arithmetic number, because the mean of its divisors is an integer number (2642055).

Almost surely, 2^128499840 is an apocalyptic number.

128499840 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 128499840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253637280).

128499840 is an abundant number, since it is smaller than the sum of its proper divisors (378774720).

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

128499840 is a wasteful number, since it uses less digits than its factorization.

128499840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3219 (or 3204 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 128499840 is about 11335.7769914550. The cubic root of 128499840 is about 504.6235668070.

It can be divided in two parts, 1284 and 99840, that added together give a square (101124 = 318²).

The spelling of 128499840 in words is "one hundred twenty-eight million, four hundred ninety-nine thousand, eight hundred forty".