28023643 has 4 divisors (see below), whose sum is σ = 28498680. Its totient is φ = 27548608.

The previous prime is 28023617. The next prime is 28023647. The reversal of 28023643 is 34632082.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28023643 - 2²¹ = 25926491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28023647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237430 + ... + 237547.

It is an arithmetic number, because the mean of its divisors is an integer number (7124670).

Almost surely, 2^28023643 is an apocalyptic number.

28023643 is a deficient number, since it is larger than the sum of its proper divisors (475037).

28023643 is an equidigital number, since it uses as much as digits as its factorization.

28023643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475036.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 28023643 is about 5293.7362042323. The cubic root of 28023643 is about 303.7443422769.

The spelling of 28023643 in words is "twenty-eight million, twenty-three thousand, six hundred forty-three".