81173112 has 32 divisors (see below), whose sum is σ = 207884880. Its totient is φ = 26397440.

The previous prime is 81173101. The next prime is 81173119. The reversal of 81173112 is 21137118.

It is a happy number.

It is a super-2 number, since 2×81173112² = 13178148223529088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81173119) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40263 + ... + 42230.

Almost surely, 2^81173112 is an apocalyptic number.

81173112 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is an amenable number.

81173112 is an abundant number, since it is smaller than the sum of its proper divisors (126711768).

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

81173112 is a wasteful number, since it uses less digits than its factorization.

81173112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82543 (or 82539 counting only the distinct ones).

The product of its digits is 336, while the sum is 24.

The square root of 81173112 is about 9009.6122003114. The cubic root of 81173112 is about 432.9828872087.

The spelling of 81173112 in words is "eighty-one million, one hundred seventy-three thousand, one hundred twelve".