123128780 has 48 divisors (see below), whose sum is σ = 273762720. Its totient is φ = 46437888.

The previous prime is 123128779. The next prime is 123128783. The reversal of 123128780 is 87821321.

It is not an unprimeable number, because it can be changed into a prime (123128783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22472 + ... + 27408.

It is an arithmetic number, because the mean of its divisors is an integer number (5703390).

Almost surely, 2^123128780 is an apocalyptic number.

123128780 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 123128780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136881360).

123128780 is an abundant number, since it is smaller than the sum of its proper divisors (150633940).

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

123128780 is a wasteful number, since it uses less digits than its factorization.

123128780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5018 (or 5016 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 123128780 is about 11096.3408383124. The cubic root of 123128780 is about 497.4924857665.

The spelling of 123128780 in words is "one hundred twenty-three million, one hundred twenty-eight thousand, seven hundred eighty".