28420473 has 4 divisors (see below), whose sum is σ = 37893968. Its totient is φ = 18946980.

The previous prime is 28420471. The next prime is 28420489. The reversal of 28420473 is 37402482.

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.

It is not a de Polignac number, because 28420473 - 2¹ = 28420471 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28420473.

It is not an unprimeable number, because it can be changed into a prime (28420471) 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, 4736743 + ... + 4736748.

It is an arithmetic number, because the mean of its divisors is an integer number (9473492).

Almost surely, 2^28420473 is an apocalyptic number.

It is an amenable number.

28420473 is a deficient number, since it is larger than the sum of its proper divisors (9473495).

28420473 is an equidigital number, since it uses as much as digits as its factorization.

28420473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9473494.

The product of its (nonzero) digits is 10752, while the sum is 30.

The square root of 28420473 is about 5331.0855367364. The cubic root of 28420473 is about 305.1713558290.

Subtracting 28420473 from its reverse (37402482), we obtain a square (8982009 = 2997²).

The spelling of 28420473 in words is "twenty-eight million, four hundred twenty thousand, four hundred seventy-three".