128820725 has 12 divisors (see below), whose sum is σ = 174259680. Its totient is φ = 93687600.

The previous prime is 128820683. The next prime is 128820737. The reversal of 128820725 is 527028821.

It is not a de Polignac number, because 128820725 - 2²² = 124626421 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 233945 + ... + 234494.

It is an arithmetic number, because the mean of its divisors is an integer number (14521640).

Almost surely, 2^128820725 is an apocalyptic number.

It is an amenable number.

128820725 is a deficient number, since it is larger than the sum of its proper divisors (45438955).

128820725 is a wasteful number, since it uses less digits than its factorization.

128820725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468460 (or 468455 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 128820725 is about 11349.9218058980. The cubic root of 128820725 is about 505.0432600264.

The spelling of 128820725 in words is "one hundred twenty-eight million, eight hundred twenty thousand, seven hundred twenty-five".