28137856 has 64 divisors (see below), whose sum is σ = 60551280. Its totient is φ = 12976128.

The previous prime is 28137847. The next prime is 28137877. The reversal of 28137856 is 65873182.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145696 + ... + 145888.

It is a vampire number, since it can be written as 3281 ⋅ 8576 (with its own digits).

Almost surely, 2^28137856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28137856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30275640).

28137856 is an abundant number, since it is smaller than the sum of its proper divisors (32413424).

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

28137856 is a wasteful number, since it uses less digits than its factorization.

28137856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291 (or 279 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 28137856 is about 5304.5127957240. The cubic root of 28137856 is about 304.1564291878.

The spelling of 28137856 in words is "twenty-eight million, one hundred thirty-seven thousand, eight hundred fifty-six".