28209636 has 144 divisors (see below), whose sum is σ = 89689600. Its totient is φ = 7278336.

The previous prime is 28209631. The next prime is 28209653. The reversal of 28209636 is 63690282.

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

It is a self number, because there is not a number n which added to its sum of digits gives 28209636.

It is not an unprimeable number, because it can be changed into a prime (28209631) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 258750 + ... + 258858.

Almost surely, 2^28209636 is an apocalyptic number.

28209636 is a gapful number since it is divisible by the number (26) 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 28209636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44844800).

28209636 is an abundant number, since it is smaller than the sum of its proper divisors (61479964).

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

28209636 is a wasteful number, since it uses less digits than its factorization.

28209636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 28209636 is about 5311.2744233376. The cubic root of 28209636 is about 304.4148451085.

The spelling of 28209636 in words is "twenty-eight million, two hundred nine thousand, six hundred thirty-six".