28157881523 has 4 divisors (see below), whose sum is σ = 28326491760. Its totient is φ = 27989271288.

The previous prime is 28157881483. The next prime is 28157881597. The reversal of 28157881523 is 32518875182.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28157881523 - 2³² = 23862914227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28157884523) 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 3 ways as a sum of consecutive naturals, for example, 84304868 + ... + 84305201.

It is an arithmetic number, because the mean of its divisors is an integer number (7081622940).

Almost surely, 2^28157881523 is an apocalyptic number.

28157881523 is a deficient number, since it is larger than the sum of its proper divisors (168610237).

28157881523 is a wasteful number, since it uses less digits than its factorization.

28157881523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168610236.

The product of its digits is 1075200, while the sum is 50.

The spelling of 28157881523 in words is "twenty-eight billion, one hundred fifty-seven million, eight hundred eighty-one thousand, five hundred twenty-three".