28181475252 has 54 divisors (see below), whose sum is σ = 82866962178. Its totient is φ = 8051849568.

The previous prime is 28181475239. The next prime is 28181475313. The reversal of 28181475252 is 25257418182.

28181475252 is a `hidden beast` number, since 2 + 8 + 1 + 81 + 47 + 525 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 24634558116 + 3546917136 = 156954^2 + 59556^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28181475198 and 28181475207.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7986183 + ... + 7989710.

Almost surely, 2^28181475252 is an apocalyptic number.

It is an amenable number.

28181475252 is an abundant number, since it is smaller than the sum of its proper divisors (54685486926).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28181475252 is a wasteful number, since it uses less digits than its factorization.

28181475252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15975917 (or 15975905 counting only the distinct ones).

The product of its digits is 358400, while the sum is 45.

The spelling of 28181475252 in words is "twenty-eight billion, one hundred eighty-one million, four hundred seventy-five thousand, two hundred fifty-two".