28120216 has 8 divisors (see below), whose sum is σ = 52725420. Its totient is φ = 14060104.

The previous prime is 28120201. The next prime is 28120217. The reversal of 28120216 is 61202182.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28120217) by changing a digit.

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 as a sum of consecutive naturals, namely, 1757506 + ... + 1757521.

Almost surely, 2^28120216 is an apocalyptic number.

It is an amenable number.

28120216 is a deficient number, since it is larger than the sum of its proper divisors (24605204).

28120216 is a wasteful number, since it uses less digits than its factorization.

28120216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3515033 (or 3515029 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 28120216 is about 5302.8497998718. The cubic root of 28120216 is about 304.0928559835.

Adding to 28120216 its reverse (61202182), we get a palindrome (89322398).

It can be divided in two parts, 2 and 8120216, that added together give a palindrome (8120218).

The spelling of 28120216 in words is "twenty-eight million, one hundred twenty thousand, two hundred sixteen".