9780028155 has 32 divisors (see below), whose sum is σ = 17390836800. Its totient is φ = 5214779136.

The previous prime is 9780028147. The next prime is 9780028157. The reversal of 9780028155 is 5518200879.

It is a happy number.

9780028155 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9780028155 - 2³ = 9780028147 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 9780028155.

It is not an unprimeable number, because it can be changed into a prime (9780028157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1004551 + ... + 1014239.

It is an arithmetic number, because the mean of its divisors is an integer number (543463650).

Almost surely, 2^9780028155 is an apocalyptic number.

9780028155 is a deficient number, since it is larger than the sum of its proper divisors (7610808645).

9780028155 is a wasteful number, since it uses less digits than its factorization.

9780028155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17180 (or 17174 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The square root of 9780028155 is about 98894.0248700598. The cubic root of 9780028155 is about 2138.5202565542.

The spelling of 9780028155 in words is "nine billion, seven hundred eighty million, twenty-eight thousand, one hundred fifty-five".