28009870 has 24 divisors (see below), whose sum is σ = 58650264. Its totient is φ = 9603216.

The previous prime is 28009831. The next prime is 28009889. The reversal of 28009870 is 7890082.

It is a happy number.

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, 28092 + ... + 29071.

It is an arithmetic number, because the mean of its divisors is an integer number (2443761).

Almost surely, 2^28009870 is an apocalyptic number.

28009870 is an abundant number, since it is smaller than the sum of its proper divisors (30640394).

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

28009870 is a wasteful number, since it uses less digits than its factorization.

28009870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57184 (or 57177 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 28009870 is about 5292.4351672930. The cubic root of 28009870 is about 303.6945729164.

The spelling of 28009870 in words is "twenty-eight million, nine thousand, eight hundred seventy".