28623840 has 144 divisors (see below), whose sum is σ = 104972112. Its totient is φ = 6537216.

The previous prime is 28623839. The next prime is 28623851. The reversal of 28623840 is 4832682.

It is a congruent number.

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, 22912 + ... + 24128.

It is an arithmetic number, because the mean of its divisors is an integer number (728973).

Almost surely, 2^28623840 is an apocalyptic number.

28623840 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 28623840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52486056).

28623840 is an abundant number, since it is smaller than the sum of its proper divisors (76348272).

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

28623840 is a wasteful number, since it uses less digits than its factorization.

28623840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249 (or 1234 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 28623840 is about 5350.1252321791. The cubic root of 28623840 is about 305.8975264546.

The spelling of 28623840 in words is "twenty-eight million, six hundred twenty-three thousand, eight hundred forty".