81975168 has 96 divisors (see below), whose sum is σ = 257376600. Its totient is φ = 24837120.

The previous prime is 81975149. The next prime is 81975169. The reversal of 81975168 is 86157918.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81975169) 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, 9438 + ... + 15906.

Almost surely, 2^81975168 is an apocalyptic number.

81975168 is a gapful number since it is divisible by the number (88) 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 81975168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128688300).

81975168 is an abundant number, since it is smaller than the sum of its proper divisors (175401432).

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

81975168 is a wasteful number, since it uses less digits than its factorization.

81975168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6500 (or 6485 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 81975168 is about 9054.0139164903. The cubic root of 81975168 is about 434.4042896110.

The spelling of 81975168 in words is "eighty-one million, nine hundred seventy-five thousand, one hundred sixty-eight".