81015712 has 12 divisors (see below), whose sum is σ = 159499746. Its totient is φ = 40507840.

The previous prime is 81015709. The next prime is 81015749. The reversal of 81015712 is 21751018.

It can be written as a sum of positive squares in only one way, i.e., 62663056 + 18352656 = 7916^2 + 4284^2 .

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1265839 + ... + 1265902.

Almost surely, 2^81015712 is an apocalyptic number.

It is an amenable number.

81015712 is a deficient number, since it is larger than the sum of its proper divisors (78484034).

81015712 is a wasteful number, since it uses less digits than its factorization.

81015712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2531751 (or 2531743 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 25.

The square root of 81015712 is about 9000.8728465633. The cubic root of 81015712 is about 432.7028453641.

The spelling of 81015712 in words is "eighty-one million, fifteen thousand, seven hundred twelve".