28613221 has 36 divisors (see below), whose sum is σ = 37929312. Its totient is φ = 21127392.

The previous prime is 28613201. The next prime is 28613237. The reversal of 28613221 is 12231682.

It is not a de Polignac number, because 28613221 - 2¹¹ = 28611173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28613201) 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 35 ways as a sum of consecutive naturals, for example, 427030 + ... + 427096.

It is an arithmetic number, because the mean of its divisors is an integer number (1053592).

Almost surely, 2^28613221 is an apocalyptic number.

It is an amenable number.

28613221 is a deficient number, since it is larger than the sum of its proper divisors (9316091).

28613221 is a wasteful number, since it uses less digits than its factorization.

28613221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 106 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 28613221 is about 5349.1327334438. The cubic root of 28613221 is about 305.8596940323.

The spelling of 28613221 in words is "twenty-eight million, six hundred thirteen thousand, two hundred twenty-one".