28193155 has 4 divisors (see below), whose sum is σ = 33831792. Its totient is φ = 22554520.

The previous prime is 28193141. The next prime is 28193183. The reversal of 28193155 is 55139182.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28193155 - 2¹⁹ = 27668867 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 28193155.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2819311 + ... + 2819320.

It is an arithmetic number, because the mean of its divisors is an integer number (8457948).

Almost surely, 2^28193155 is an apocalyptic number.

28193155 is a deficient number, since it is larger than the sum of its proper divisors (5638637).

28193155 is an equidigital number, since it uses as much as digits as its factorization.

28193155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5638636.

The product of its digits is 10800, while the sum is 34.

The square root of 28193155 is about 5309.7226857907. The cubic root of 28193155 is about 304.3555504946.

The spelling of 28193155 in words is "twenty-eight million, one hundred ninety-three thousand, one hundred fifty-five".