81149712 has 40 divisors (see below), whose sum is σ = 239585856. Its totient is φ = 23185536.

The previous prime is 81149711. The next prime is 81149749. The reversal of 81149712 is 21794118.

It is not an unprimeable number, because it can be changed into a prime (81149711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120423 + ... + 121094.

Almost surely, 2^81149712 is an apocalyptic number.

It is an amenable number.

81149712 is an abundant number, since it is smaller than the sum of its proper divisors (158436144).

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

81149712 is a wasteful number, since it uses less digits than its factorization.

81149712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241535 (or 241529 counting only the distinct ones).

The product of its digits is 4032, while the sum is 33.

The square root of 81149712 is about 9008.3134936568. The cubic root of 81149712 is about 432.9412774808.

The spelling of 81149712 in words is "eighty-one million, one hundred forty-nine thousand, seven hundred twelve".