28639800 has 144 divisors (see below), whose sum is σ = 109970640. Its totient is φ = 6543360.

The previous prime is 28639799. The next prime is 28639817. The reversal of 28639800 is 893682.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 11464 + ... + 13736.

It is an arithmetic number, because the mean of its divisors is an integer number (763685).

Almost surely, 2^28639800 is an apocalyptic number.

28639800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28639800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54985320).

28639800 is an abundant number, since it is smaller than the sum of its proper divisors (81330840).

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

28639800 is a wasteful number, since it uses less digits than its factorization.

28639800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2302 (or 2290 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 28639800 is about 5351.6165781939. The cubic root of 28639800 is about 305.9543697179.

The spelling of 28639800 in words is "twenty-eight million, six hundred thirty-nine thousand, eight hundred".