81268172 has 6 divisors (see below), whose sum is σ = 142219308. Its totient is φ = 40634084.

The previous prime is 81268171. The next prime is 81268181. The reversal of 81268172 is 27186218.

It is not an unprimeable number, because it can be changed into a prime (81268171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10158518 + ... + 10158525.

It is an arithmetic number, because the mean of its divisors is an integer number (23703218).

Almost surely, 2^81268172 is an apocalyptic number.

It is an amenable number.

81268172 is a deficient number, since it is larger than the sum of its proper divisors (60951136).

81268172 is a wasteful number, since it uses less digits than its factorization.

81268172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20317047 (or 20317045 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 81268172 is about 9014.8861335016. The cubic root of 81268172 is about 433.1518401035.

The spelling of 81268172 in words is "eighty-one million, two hundred sixty-eight thousand, one hundred seventy-two".