28221669 has 64 divisors (see below), whose sum is σ = 52224000. Its totient is φ = 14696640.

The previous prime is 28221623. The next prime is 28221689. The reversal of 28221669 is 96612282.

It is a happy number.

It is not a de Polignac number, because 28221669 - 2⁷ = 28221541 is a prime.

It is a super-2 number, since 2×28221669² = 1592925202291122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28221689) 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 63 ways as a sum of consecutive naturals, for example, 104004 + ... + 104274.

It is an arithmetic number, because the mean of its divisors is an integer number (816000).

Almost surely, 2^28221669 is an apocalyptic number.

28221669 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28221669 is a deficient number, since it is larger than the sum of its proper divisors (24002331).

28221669 is a wasteful number, since it uses less digits than its factorization.

28221669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335 (or 329 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 28221669 is about 5312.4070815403. The cubic root of 28221669 is about 304.4581223197.

The spelling of 28221669 in words is "twenty-eight million, two hundred twenty-one thousand, six hundred sixty-nine".