81334172 has 6 divisors (see below), whose sum is σ = 142334808. Its totient is φ = 40667084.

The previous prime is 81334157. The next prime is 81334207. The reversal of 81334172 is 27143318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10166768 + ... + 10166775.

It is an arithmetic number, because the mean of its divisors is an integer number (23722468).

Almost surely, 2^81334172 is an apocalyptic number.

It is an amenable number.

81334172 is a deficient number, since it is larger than the sum of its proper divisors (61000636).

81334172 is a wasteful number, since it uses less digits than its factorization.

81334172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20333547 (or 20333545 counting only the distinct ones).

The product of its digits is 4032, while the sum is 29.

The square root of 81334172 is about 9018.5460025439. The cubic root of 81334172 is about 433.2690663403.

The spelling of 81334172 in words is "eighty-one million, three hundred thirty-four thousand, one hundred seventy-two".