28621320 has 128 divisors (see below), whose sum is σ = 105719040. Its totient is φ = 6036480.

The previous prime is 28621301. The next prime is 28621337. The reversal of 28621320 is 2312682.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9610 + ... + 12230.

It is an arithmetic number, because the mean of its divisors is an integer number (825930).

Almost surely, 2^28621320 is an apocalyptic number.

28621320 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 28621320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52859520).

28621320 is an abundant number, since it is smaller than the sum of its proper divisors (77097720).

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

28621320 is a wasteful number, since it uses less digits than its factorization.

28621320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655 (or 2651 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 28621320 is about 5349.8897184895. The cubic root of 28621320 is about 305.8885492712. Note that the first 3 decimals are identical.

The spelling of 28621320 in words is "twenty-eight million, six hundred twenty-one thousand, three hundred twenty".