28291020 has 48 divisors (see below), whose sum is σ = 80047968. Its totient is φ = 7464960.

The previous prime is 28291013. The next prime is 28291063. The reversal of 28291020 is 2019282.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3390 + ... + 8250.

It is an arithmetic number, because the mean of its divisors is an integer number (1667666).

Almost surely, 2^28291020 is an apocalyptic number.

28291020 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 28291020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40023984).

28291020 is an abundant number, since it is smaller than the sum of its proper divisors (51756948).

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

28291020 is a wasteful number, since it uses less digits than its factorization.

28291020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4970 (or 4968 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 28291020 is about 5318.9303435935. The cubic root of 28291020 is about 304.7073067729.

The spelling of 28291020 in words is "twenty-eight million, two hundred ninety-one thousand, twenty".