81947056 has 10 divisors (see below), whose sum is σ = 158772452. Its totient is φ = 40973520.

The previous prime is 81947029. The next prime is 81947071. The reversal of 81947056 is 65074918.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2560830 + ... + 2560861.

Almost surely, 2^81947056 is an apocalyptic number.

It is an amenable number.

81947056 is a deficient number, since it is larger than the sum of its proper divisors (76825396).

81947056 is a wasteful number, since it uses less digits than its factorization.

81947056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5121699 (or 5121693 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 81947056 is about 9052.4613227564. The cubic root of 81947056 is about 434.3546267276.

The spelling of 81947056 in words is "eighty-one million, nine hundred forty-seven thousand, fifty-six".