28971726555591 has 12 divisors (see below), whose sum is σ = 42114597557032. Its totient is φ = 19191462176016.

The previous prime is 28971726555523. The next prime is 28971726555661. The reversal of 28971726555591 is 19555562717982.

28971726555591 is a `hidden beast` number, since 2 + 8 + 9 + 7 + 1 + 7 + 2 + 65 + 5 + 559 + 1 = 666.

It is not a de Polignac number, because 28971726555591 - 2³⁸ = 28696848648647 is a prime.

It is a super-2 number, since 2×28971726555591² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28971726555691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10251848041 + ... + 10251850866.

Almost surely, 2^{28971726555591} is an apocalyptic number.

28971726555591 is a deficient number, since it is larger than the sum of its proper divisors (13142871001441).

28971726555591 is a wasteful number, since it uses less digits than its factorization.

28971726555591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20503699070 (or 20503699067 counting only the distinct ones).

The product of its digits is 476280000, while the sum is 72.

The spelling of 28971726555591 in words is "twenty-eight trillion, nine hundred seventy-one billion, seven hundred twenty-six million, five hundred fifty-five thousand, five hundred ninety-one".