81451712 has 28 divisors (see below), whose sum is σ = 162068256. Its totient is φ = 40615680.

The previous prime is 81451681. The next prime is 81451723. The reversal of 81451712 is 21715418.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 25433 + ... + 28455.

It is an arithmetic number, because the mean of its divisors is an integer number (5788152).

Almost surely, 2^81451712 is an apocalyptic number.

It is an amenable number.

81451712 is a deficient number, since it is larger than the sum of its proper divisors (80616544).

81451712 is a wasteful number, since it uses less digits than its factorization.

81451712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3456 (or 3446 counting only the distinct ones).

The product of its digits is 2240, while the sum is 29.

The square root of 81451712 is about 9025.0602214057. The cubic root of 81451712 is about 433.4776786713.

The spelling of 81451712 in words is "eighty-one million, four hundred fifty-one thousand, seven hundred twelve".