81724616 has 16 divisors (see below), whose sum is σ = 153878400. Its totient is φ = 40690384.

The previous prime is 81724607. The next prime is 81724619. The reversal of 81724616 is 61642718.

It is not an unprimeable number, because it can be changed into a prime (81724619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19460 + ... + 23283.

It is an arithmetic number, because the mean of its divisors is an integer number (9617400).

Almost surely, 2^81724616 is an apocalyptic number.

It is an amenable number.

81724616 is a deficient number, since it is larger than the sum of its proper divisors (72153784).

81724616 is a wasteful number, since it uses less digits than its factorization.

81724616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42988 (or 42984 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 81724616 is about 9040.1668126202. The cubic root of 81724616 is about 433.9612613812.

The spelling of 81724616 in words is "eighty-one million, seven hundred twenty-four thousand, six hundred sixteen".