28634221 has 8 divisors (see below), whose sum is σ = 35699904. Its totient is φ = 22312320.

The previous prime is 28634219. The next prime is 28634251. The reversal of 28634221 is 12243682.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28634221 - 2¹ = 28634219 is a prime.

It is a super-2 number, since 2×28634221² = 1639837224553682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28634221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28634201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185860 + ... + 186013.

It is an arithmetic number, because the mean of its divisors is an integer number (4462488).

Almost surely, 2^28634221 is an apocalyptic number.

It is an amenable number.

28634221 is a deficient number, since it is larger than the sum of its proper divisors (7065683).

28634221 is a wasteful number, since it uses less digits than its factorization.

28634221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371891.

The product of its digits is 4608, while the sum is 28.

The square root of 28634221 is about 5351.0953084392. The cubic root of 28634221 is about 305.9345019083.

The spelling of 28634221 in words is "twenty-eight million, six hundred thirty-four thousand, two hundred twenty-one".