28663140 has 96 divisors (see below), whose sum is σ = 88470144. Its totient is φ = 6876160.

The previous prime is 28663121. The next prime is 28663157. The reversal of 28663140 is 4136682.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28663098 and 28663107.

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, 90262 + ... + 90578.

It is an arithmetic number, because the mean of its divisors is an integer number (921564).

Almost surely, 2^28663140 is an apocalyptic number.

28663140 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 28663140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44235072).

28663140 is an abundant number, since it is smaller than the sum of its proper divisors (59807004).

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

28663140 is a wasteful number, since it uses less digits than its factorization.

28663140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 28663140 is about 5353.7967835920. The cubic root of 28663140 is about 306.0374596373.

It can be divided in two parts, 2866 and 3140, that added together give a palindrome (6006).

The spelling of 28663140 in words is "twenty-eight million, six hundred sixty-three thousand, one hundred forty".