28212240 has 120 divisors (see below), whose sum is σ = 101779200. Its totient is φ = 6445824.

The previous prime is 28212227. The next prime is 28212251. The reversal of 28212240 is 4221282.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10561 + ... + 12959.

It is an arithmetic number, because the mean of its divisors is an integer number (848160).

Almost surely, 2^28212240 is an apocalyptic number.

28212240 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 28212240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50889600).

28212240 is an abundant number, since it is smaller than the sum of its proper divisors (73566960).

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

28212240 is a wasteful number, since it uses less digits than its factorization.

28212240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2429 (or 2416 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 28212240 is about 5311.5195565864. The cubic root of 28212240 is about 304.4242115517.

The spelling of 28212240 in words is "twenty-eight million, two hundred twelve thousand, two hundred forty".