28133661 has 8 divisors (see below), whose sum is σ = 39485920. Its totient is φ = 17768592.

The previous prime is 28133659. The next prime is 28133671. The reversal of 28133661 is 16633182.

28133661 = T₄₈₆ + T₄₈₇ + ... + T₆₅₆.

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

It is not a de Polignac number, because 28133661 - 2¹ = 28133659 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 (28133621) 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, 246730 + ... + 246843.

It is an arithmetic number, because the mean of its divisors is an integer number (4935740).

Almost surely, 2^28133661 is an apocalyptic number.

It is an amenable number.

28133661 is a deficient number, since it is larger than the sum of its proper divisors (11352259).

28133661 is a wasteful number, since it uses less digits than its factorization.

28133661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493595.

The product of its digits is 5184, while the sum is 30.

The square root of 28133661 is about 5304.1173629549. The cubic root of 28133661 is about 304.1413131387.

The spelling of 28133661 in words is "twenty-eight million, one hundred thirty-three thousand, six hundred sixty-one".