28573421 has 4 divisors (see below), whose sum is σ = 28585500. Its totient is φ = 28561344.

The previous prime is 28573417. The next prime is 28573459. The reversal of 28573421 is 12437582.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2706025 + 25867396 = 1645^2 + 5086^2 .

It is a cyclic number.

It is not a de Polignac number, because 28573421 - 2² = 28573417 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 (28573621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1196 + ... + 7653.

It is an arithmetic number, because the mean of its divisors is an integer number (7146375).

Almost surely, 2^28573421 is an apocalyptic number.

It is an amenable number.

28573421 is a deficient number, since it is larger than the sum of its proper divisors (12079).

28573421 is an equidigital number, since it uses as much as digits as its factorization.

28573421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12078.

The product of its digits is 13440, while the sum is 32.

The square root of 28573421 is about 5345.4112096264. The cubic root of 28573421 is about 305.7178148131.

The spelling of 28573421 in words is "twenty-eight million, five hundred seventy-three thousand, four hundred twenty-one".