28624640 has 144 divisors (see below), whose sum is σ = 79470720. Its totient is φ = 9768960.

The previous prime is 28624619. The next prime is 28624649. The reversal of 28624640 is 4642682.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 28624597 and 28624606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28624649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267467 + ... + 267573.

It is an arithmetic number, because the mean of its divisors is an integer number (551880).

Almost surely, 2^28624640 is an apocalyptic number.

28624640 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 28624640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39735360).

28624640 is an abundant number, since it is smaller than the sum of its proper divisors (50846080).

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

28624640 is a wasteful number, since it uses less digits than its factorization.

28624640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 28624640 is about 5350.1999962618. The cubic root of 28624640 is about 305.9003762440.

The spelling of 28624640 in words is "twenty-eight million, six hundred twenty-four thousand, six hundred forty".