28080640 has 80 divisors (see below), whose sum is σ = 76995072. Its totient is φ = 9621504.

The previous prime is 28080623. The next prime is 28080653. The reversal of 28080640 is 4608082.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 28080599 and 28080608.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17137 + ... + 18703.

Almost surely, 2^28080640 is an apocalyptic number.

28080640 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 28080640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38497536).

28080640 is an abundant number, since it is smaller than the sum of its proper divisors (48914432).

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

28080640 is an equidigital number, since it uses as much as digits as its factorization.

28080640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1597 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 28080640 is about 5299.1169075611. The cubic root of 28080640 is about 303.9501303237.

The spelling of 28080640 in words is "twenty-eight million, eighty thousand, six hundred forty".