28724172255 has 24 divisors (see below), whose sum is σ = 49977895968. Its totient is φ = 15261302976.

The previous prime is 28724172193. The next prime is 28724172299. The reversal of 28724172255 is 55227142782.

28724172255 is a `hidden beast` number, since 2 + 8 + 7 + 2 + 417 + 225 + 5 = 666.

It is not a de Polignac number, because 28724172255 - 2¹⁷ = 28724041183 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 28724172255.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1201692 + ... + 1225361.

It is an arithmetic number, because the mean of its divisors is an integer number (2082412332).

Almost surely, 2^28724172255 is an apocalyptic number.

28724172255 is a deficient number, since it is larger than the sum of its proper divisors (21253723713).

28724172255 is a wasteful number, since it uses less digits than its factorization.

28724172255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2427327 (or 2427324 counting only the distinct ones).

The product of its digits is 627200, while the sum is 45.

The spelling of 28724172255 in words is "twenty-eight billion, seven hundred twenty-four million, one hundred seventy-two thousand, two hundred fifty-five".