28212320 has 24 divisors (see below), whose sum is σ = 66651984. Its totient is φ = 11284864.

The previous prime is 28212311. The next prime is 28212323. The reversal of 28212320 is 2321282.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 28212292 and 28212301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28212323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88004 + ... + 88323.

It is an arithmetic number, because the mean of its divisors is an integer number (2777166).

Almost surely, 2^28212320 is an apocalyptic number.

28212320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28212320 is an abundant number, since it is smaller than the sum of its proper divisors (38439664).

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

28212320 is a wasteful number, since it uses less digits than its factorization.

28212320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176342 (or 176334 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 28212320 is about 5311.5270873827. The cubic root of 28212320 is about 304.4244992982.

The spelling of 28212320 in words is "twenty-eight million, two hundred twelve thousand, three hundred twenty".