28905870 has 64 divisors (see below), whose sum is σ = 80663040. Its totient is φ = 6492288.

The previous prime is 28905853. The next prime is 28905907. The reversal of 28905870 is 7850982.

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, 11224 + ... + 13556.

It is an arithmetic number, because the mean of its divisors is an integer number (1260360).

Almost surely, 2^28905870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28905870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40331520).

28905870 is an abundant number, since it is smaller than the sum of its proper divisors (51757170).

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

28905870 is a wasteful number, since it uses less digits than its factorization.

28905870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 28905870 is about 5376.4179525033. The cubic root of 28905870 is about 306.8989117107.

The spelling of 28905870 in words is "twenty-eight million, nine hundred five thousand, eight hundred seventy".