28212111 has 8 divisors (see below), whose sum is σ = 41795760. Its totient is φ = 18808056.

The previous prime is 28212103. The next prime is 28212127. The reversal of 28212111 is 11121282.

It is not a de Polignac number, because 28212111 - 2³ = 28212103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28212101) 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, 522420 + ... + 522473.

It is an arithmetic number, because the mean of its divisors is an integer number (5224470).

Almost surely, 2^28212111 is an apocalyptic number.

28212111 is a deficient number, since it is larger than the sum of its proper divisors (13583649).

28212111 is a wasteful number, since it uses less digits than its factorization.

28212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044902 (or 1044896 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

The square root of 28212111 is about 5311.5074131550. The cubic root of 28212111 is about 304.4237475595.

Adding to 28212111 its reverse (11121282), we get a palindrome (39333393).

The spelling of 28212111 in words is "twenty-eight million, two hundred twelve thousand, one hundred eleven".