28673640 has 96 divisors (see below), whose sum is σ = 97269120. Its totient is φ = 7311744.

The previous prime is 28673639. The next prime is 28673653. The reversal of 28673640 is 4637682.

28673640 is a `hidden beast` number, since 2 + 8 + 6 + 7 + 3 + 640 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 28673595 and 28673604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6549 + ... + 10011.

It is an arithmetic number, because the mean of its divisors is an integer number (1013220).

Almost surely, 2^28673640 is an apocalyptic number.

28673640 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 28673640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48634560).

28673640 is an abundant number, since it is smaller than the sum of its proper divisors (68595480).

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

28673640 is a wasteful number, since it uses less digits than its factorization.

28673640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3503 (or 3496 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 28673640 is about 5354.7773062939. Note that the first 3 decimals coincide. The cubic root of 28673640 is about 306.0748247111.

The spelling of 28673640 in words is "twenty-eight million, six hundred seventy-three thousand, six hundred forty".