128000820 has 96 divisors (see below), whose sum is σ = 385354368. Its totient is φ = 31629312.

The previous prime is 128000813. The next prime is 128000827. The reversal of 128000820 is 28000821.

It is an interprime number because it is at equal distance from previous prime (128000813) and next prime (128000827).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128000827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67404 + ... + 69276.

It is an arithmetic number, because the mean of its divisors is an integer number (4014108).

Almost surely, 2^128000820 is an apocalyptic number.

128000820 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 128000820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192677184).

128000820 is an abundant number, since it is smaller than the sum of its proper divisors (257353548).

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

128000820 is a wasteful number, since it uses less digits than its factorization.

128000820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1969 (or 1967 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 128000820 is about 11313.7447381493. The cubic root of 128000820 is about 503.9694961382.

Subtracting from 128000820 its reverse (28000821), we obtain a palindrome (99999999).

The spelling of 128000820 in words is "one hundred twenty-eight million, eight hundred twenty", and thus it is an aban number.