128633920 has 28 divisors (see below), whose sum is σ = 306310284. Its totient is φ = 51453440.

The previous prime is 128633909. The next prime is 128633927. The reversal of 128633920 is 29336821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 102090816 + 26543104 = 10104^2 + 5152^2 .

It is not an unprimeable number, because it can be changed into a prime (128633927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200671 + ... + 201310.

It is an arithmetic number, because the mean of its divisors is an integer number (10939653).

Almost surely, 2^128633920 is an apocalyptic number.

128633920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128633920 is an abundant number, since it is smaller than the sum of its proper divisors (177676364).

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

128633920 is an equidigital number, since it uses as much as digits as its factorization.

128633920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401998 (or 401988 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 128633920 is about 11341.6894685051. The cubic root of 128633920 is about 504.7990181507.

The spelling of 128633920 in words is "one hundred twenty-eight million, six hundred thirty-three thousand, nine hundred twenty".