28868856 has 64 divisors (see below), whose sum is σ = 77047200. Its totient is φ = 8982528.

The previous prime is 28868837. The next prime is 28868869. The reversal of 28868856 is 65886882.

28868856 = 34² + 35² + ... + 442².

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a junction number, because it is equal to n+sod(n) for n = 28868799 and 28868808.

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 15 ways as a sum of consecutive naturals, for example, 70380 + ... + 70788.

Almost surely, 2^28868856 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 28868856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38523600).

28868856 is an abundant number, since it is smaller than the sum of its proper divisors (48178344).

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

28868856 is a wasteful number, since it uses less digits than its factorization.

28868856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608 (or 604 counting only the distinct ones).

The product of its digits is 1474560, while the sum is 51.

The square root of 28868856 is about 5372.9745951382. The cubic root of 28868856 is about 306.7678609540.

The spelling of 28868856 in words is "twenty-eight million, eight hundred sixty-eight thousand, eight hundred fifty-six".