28122201 has 8 divisors (see below), whose sum is σ = 41662560. Its totient is φ = 18748116.

The previous prime is 28122191. The next prime is 28122203. The reversal of 28122201 is 10222182.

It is a happy number.

It is not a de Polignac number, because 28122201 - 2¹¹ = 28120153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28122203) 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 7 ways as a sum of consecutive naturals, for example, 520755 + ... + 520808.

It is an arithmetic number, because the mean of its divisors is an integer number (5207820).

Almost surely, 2^28122201 is an apocalyptic number.

It is an amenable number.

28122201 is a deficient number, since it is larger than the sum of its proper divisors (13540359).

28122201 is a wasteful number, since it uses less digits than its factorization.

28122201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1041572 (or 1041566 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 28122201 is about 5303.0369600824. The cubic root of 28122201 is about 304.1000110983.

Adding to 28122201 its reverse (10222182), we get a palindrome (38344383).

The spelling of 28122201 in words is "twenty-eight million, one hundred twenty-two thousand, two hundred one".