28065821 has 8 divisors (see below), whose sum is σ = 32174784. Its totient is φ = 23981760.

The previous prime is 28065809. The next prime is 28065839. The reversal of 28065821 is 12856082.

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 28065821 - 2¹⁰ = 28064797 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 (28065841) 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, 3740 + ... + 8373.

It is an arithmetic number, because the mean of its divisors is an integer number (4021848).

Almost surely, 2^28065821 is an apocalyptic number.

It is an amenable number.

28065821 is a deficient number, since it is larger than the sum of its proper divisors (4108963).

28065821 is a wasteful number, since it uses less digits than its factorization.

28065821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12451.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 28065821 is about 5297.7184711912. The cubic root of 28065821 is about 303.8966530341.

The spelling of 28065821 in words is "twenty-eight million, sixty-five thousand, eight hundred twenty-one".