81042712 has 8 divisors (see below), whose sum is σ = 151955100. Its totient is φ = 40521352.

The previous prime is 81042701. The next prime is 81042727. The reversal of 81042712 is 21724018.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a nialpdrome in base 14.

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, 5065162 + ... + 5065177.

Almost surely, 2^81042712 is an apocalyptic number.

It is an amenable number.

81042712 is a deficient number, since it is larger than the sum of its proper divisors (70912388).

81042712 is a wasteful number, since it uses less digits than its factorization.

81042712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10130345 (or 10130341 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 81042712 is about 9002.3725761601. The cubic root of 81042712 is about 432.7509087949.

It can be divided in two parts, 8104 and 2712, that added together give a square (10816 = 104²).

The spelling of 81042712 in words is "eighty-one million, forty-two thousand, seven hundred twelve".