28198523 has 4 divisors (see below), whose sum is σ = 28227480. Its totient is φ = 28169568.

The previous prime is 28198501. The next prime is 28198537. The reversal of 28198523 is 32589182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32589182 = 2 ⋅16294591.

It is a cyclic number.

It is not a de Polignac number, because 28198523 - 2¹² = 28194427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28198553) 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, 12965 + ... + 14982.

It is an arithmetic number, because the mean of its divisors is an integer number (7056870).

Almost surely, 2^28198523 is an apocalyptic number.

28198523 is a deficient number, since it is larger than the sum of its proper divisors (28957).

28198523 is a wasteful number, since it uses less digits than its factorization.

28198523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28956.

The product of its digits is 34560, while the sum is 38.

The square root of 28198523 is about 5310.2281495243. The cubic root of 28198523 is about 304.3748657848.

The spelling of 28198523 in words is "twenty-eight million, one hundred ninety-eight thousand, five hundred twenty-three".