128820906 has 12 divisors (see below), whose sum is σ = 279112002. Its totient is φ = 42940296.

The previous prime is 128820877. The next prime is 128820941. The reversal of 128820906 is 609028821.

It can be written as a sum of positive squares in only one way, i.e., 78481881 + 50339025 = 8859^2 + 7095^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3578341 + ... + 3578376.

Almost surely, 2^128820906 is an apocalyptic number.

128820906 is an abundant number, since it is smaller than the sum of its proper divisors (150291096).

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

128820906 is a wasteful number, since it uses less digits than its factorization.

128820906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7156725 (or 7156722 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 128820906 is about 11349.9297795185. The cubic root of 128820906 is about 505.0434965639.

The spelling of 128820906 in words is "one hundred twenty-eight million, eight hundred twenty thousand, nine hundred six".