28398870 has 64 divisors (see below), whose sum is σ = 76515840. Its totient is φ = 7494624.

The previous prime is 28398847. The next prime is 28398889. The reversal of 28398870 is 7889382.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28399 + ... + 29381.

It is an arithmetic number, because the mean of its divisors is an integer number (1195560).

Almost surely, 2^28398870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28398870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38257920).

28398870 is an abundant number, since it is smaller than the sum of its proper divisors (48116970).

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

28398870 is a wasteful number, since it uses less digits than its factorization.

28398870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106 (or 1100 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 28398870 is about 5329.0590163743. The cubic root of 28398870 is about 305.0940138380.

The spelling of 28398870 in words is "twenty-eight million, three hundred ninety-eight thousand, eight hundred seventy".