28979497871 has 4 divisors (see below), whose sum is σ = 29200715544. Its totient is φ = 28758280200.

The previous prime is 28979497853. The next prime is 28979497907. The reversal of 28979497871 is 17879497982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17879497982 = 2 ⋅8939748991.

It is a cyclic number.

It is not a de Polignac number, because 28979497871 - 2²⁶ = 28912389007 is a prime.

It is a super-2 number, since 2×28979497871² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28979497795 and 28979497804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28979497571) 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, 110608640 + ... + 110608901.

It is an arithmetic number, because the mean of its divisors is an integer number (7300178886).

Almost surely, 2^28979497871 is an apocalyptic number.

28979497871 is a deficient number, since it is larger than the sum of its proper divisors (221217673).

28979497871 is a wasteful number, since it uses less digits than its factorization.

28979497871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221217672.

The product of its digits is 128024064, while the sum is 71.

The spelling of 28979497871 in words is "twenty-eight billion, nine hundred seventy-nine million, four hundred ninety-seven thousand, eight hundred seventy-one".