28293820 has 24 divisors (see below), whose sum is σ = 59724000. Its totient is φ = 11259072.

The previous prime is 28293781. The next prime is 28293823. The reversal of 28293820 is 2839282.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28293823) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 426 + ... + 7534.

It is an arithmetic number, because the mean of its divisors is an integer number (2488500).

Almost surely, 2^28293820 is an apocalyptic number.

28293820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28293820 is an abundant number, since it is smaller than the sum of its proper divisors (31430180).

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

28293820 is a wasteful number, since it uses less digits than its factorization.

28293820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7317 (or 7315 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28293820 is about 5319.1935478980. The cubic root of 28293820 is about 304.7173588708.

The spelling of 28293820 in words is "twenty-eight million, two hundred ninety-three thousand, eight hundred twenty".