12172537728 has 192 divisors, whose sum is σ = 37822293600. Its totient is φ = 3735465984.

The previous prime is 12172537709. The next prime is 12172537747. The reversal of 12172537728 is 82773527121.

12172537728 is a `hidden beast` number, since 1 + 21 + 72 + 537 + 7 + 28 = 666.

It is an interprime number because it is at equal distance from previous prime (12172537709) and next prime (12172537747).

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7292478 + ... + 7294146.

Almost surely, 2^12172537728 is an apocalyptic number.

12172537728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12172537728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18911146800).

12172537728 is an abundant number, since it is smaller than the sum of its proper divisors (25649755872).

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

12172537728 is a wasteful number, since it uses less digits than its factorization.

12172537728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2189 (or 2174 counting only the distinct ones).

The product of its digits is 329280, while the sum is 45.

The spelling of 12172537728 in words is "twelve billion, one hundred seventy-two million, five hundred thirty-seven thousand, seven hundred twenty-eight".