81724684 has 6 divisors (see below), whose sum is σ = 143018204. Its totient is φ = 40862340.

The previous prime is 81724667. The next prime is 81724717. The reversal of 81724684 is 48642718.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215582 + ... + 10215589.

Almost surely, 2^81724684 is an apocalyptic number.

It is an amenable number.

81724684 is a deficient number, since it is larger than the sum of its proper divisors (61293520).

81724684 is a wasteful number, since it uses less digits than its factorization.

81724684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20431175 (or 20431173 counting only the distinct ones).

The product of its digits is 86016, while the sum is 40.

The square root of 81724684 is about 9040.1705736120. The cubic root of 81724684 is about 433.9613817422.

The spelling of 81724684 in words is "eighty-one million, seven hundred twenty-four thousand, six hundred eighty-four".