28058215 has 4 divisors (see below), whose sum is σ = 33669864. Its totient is φ = 22446568.

The previous prime is 28058213. The next prime is 28058221. The reversal of 28058215 is 51285082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51285082 = 2 ⋅25642541.

It is a cyclic number.

It is not a de Polignac number, because 28058215 - 2¹ = 28058213 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28058213) 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, 2805817 + ... + 2805826.

It is an arithmetic number, because the mean of its divisors is an integer number (8417466).

Almost surely, 2^28058215 is an apocalyptic number.

28058215 is a deficient number, since it is larger than the sum of its proper divisors (5611649).

28058215 is an equidigital number, since it uses as much as digits as its factorization.

28058215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5611648.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 28058215 is about 5297.0005663583. Note that the first 3 decimals coincide. The cubic root of 28058215 is about 303.8691979696.

The spelling of 28058215 in words is "twenty-eight million, fifty-eight thousand, two hundred fifteen".