28707840 has 264 divisors, whose sum is σ = 114959520. Its totient is φ = 6488064.

The previous prime is 28707827. The next prime is 28707857. The reversal of 28707840 is 4870782.

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 = 28707795 and 28707804.

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, 322516 + ... + 322604.

Almost surely, 2^28707840 is an apocalyptic number.

28707840 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 28707840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57479760).

28707840 is an abundant number, since it is smaller than the sum of its proper divisors (86251680).

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

28707840 is a wasteful number, since it uses less digits than its factorization.

28707840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 28707840 is about 5357.9697647523. The cubic root of 28707840 is about 306.1964648890.

The spelling of 28707840 in words is "twenty-eight million, seven hundred seven thousand, eight hundred forty".