28421280 has 288 divisors, whose sum is σ = 108972864. Its totient is φ = 6967296.

The previous prime is 28421273. The next prime is 28421311. The reversal of 28421280 is 8212482.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

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 47 ways as a sum of consecutive naturals, for example, 660939 + ... + 660981.

It is an arithmetic number, because the mean of its divisors is an integer number (378378).

Almost surely, 2^28421280 is an apocalyptic number.

28421280 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 28421280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54486432).

28421280 is an abundant number, since it is smaller than the sum of its proper divisors (80551584).

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

28421280 is a wasteful number, since it uses less digits than its factorization.

28421280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 28421280 is about 5331.1612243488. The cubic root of 28421280 is about 305.1742442510.

The spelling of 28421280 in words is "twenty-eight million, four hundred twenty-one thousand, two hundred eighty".