28605381531 has 8 divisors (see below), whose sum is σ = 38709770304. Its totient is φ = 18785623560.

The previous prime is 28605381529. The next prime is 28605381557. The reversal of 28605381531 is 13518350682.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28605381531 - 2¹ = 28605381529 is a prime.

It is a super-2 number, since 2×28605381531² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28605381031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71157465 + ... + 71157866.

It is an arithmetic number, because the mean of its divisors is an integer number (4838721288).

Almost surely, 2^28605381531 is an apocalyptic number.

28605381531 is a deficient number, since it is larger than the sum of its proper divisors (10104388773).

28605381531 is a wasteful number, since it uses less digits than its factorization.

28605381531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142315401.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 28605381531 in words is "twenty-eight billion, six hundred five million, three hundred eighty-one thousand, five hundred thirty-one".