128765920 has 48 divisors (see below), whose sum is σ = 312445728. Its totient is φ = 50112000.

The previous prime is 128765911. The next prime is 128765927. The reversal of 128765920 is 29567821.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128765927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4956 + ... + 16795.

It is an arithmetic number, because the mean of its divisors is an integer number (6509286).

Almost surely, 2^128765920 is an apocalyptic number.

128765920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128765920 is an abundant number, since it is smaller than the sum of its proper divisors (183679808).

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

128765920 is a wasteful number, since it uses less digits than its factorization.

128765920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21803 (or 21795 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 128765920 is about 11347.5072152434. The cubic root of 128765920 is about 504.9716286384.

The spelling of 128765920 in words is "one hundred twenty-eight million, seven hundred sixty-five thousand, nine hundred twenty".