28570513 has 4 divisors (see below), whose sum is σ = 28891620. Its totient is φ = 28249408.

The previous prime is 28570511. The next prime is 28570517. The reversal of 28570513 is 31507582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31507582 = 2 ⋅15753791.

It can be written as a sum of positive squares in 2 ways, for example, as 15233409 + 13337104 = 3903^2 + 3652^2 .

It is a cyclic number.

It is not a de Polignac number, because 28570513 - 2¹ = 28570511 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28570511) 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, 160420 + ... + 160597.

It is an arithmetic number, because the mean of its divisors is an integer number (7222905).

Almost surely, 2^28570513 is an apocalyptic number.

It is an amenable number.

28570513 is a deficient number, since it is larger than the sum of its proper divisors (321107).

28570513 is an equidigital number, since it uses as much as digits as its factorization.

28570513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321106.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 28570513 is about 5345.1391936974. The cubic root of 28570513 is about 305.7074431981.

The spelling of 28570513 in words is "twenty-eight million, five hundred seventy thousand, five hundred thirteen".