28640533 has 4 divisors (see below), whose sum is σ = 28846720. Its totient is φ = 28434348.

The previous prime is 28640527. The next prime is 28640551. The reversal of 28640533 is 33504682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 33504682 = 2 ⋅16752341.

It is a cyclic number.

It is not a de Polignac number, because 28640533 - 2¹³ = 28632341 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28640495 and 28640504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28640503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102885 + ... + 103162.

It is an arithmetic number, because the mean of its divisors is an integer number (7211680).

Almost surely, 2^28640533 is an apocalyptic number.

It is an amenable number.

28640533 is a deficient number, since it is larger than the sum of its proper divisors (206187).

28640533 is a wasteful number, since it uses less digits than its factorization.

28640533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206186.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 28640533 is about 5351.6850617352. The cubic root of 28640533 is about 305.9569798692.

The spelling of 28640533 in words is "twenty-eight million, six hundred forty thousand, five hundred thirty-three".