81684876 has 192 divisors, whose sum is σ = 256901120. Its totient is φ = 19595520.

The previous prime is 81684853. The next prime is 81684893. The reversal of 81684876 is 67848618.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 643125 + ... + 643251.

Almost surely, 2^81684876 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81684876, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128450560).

81684876 is an abundant number, since it is smaller than the sum of its proper divisors (175216244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81684876 is a wasteful number, since it uses less digits than its factorization.

81684876 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 202 counting only the distinct ones).

The product of its digits is 516096, while the sum is 48.

The square root of 81684876 is about 9037.9685770642. The cubic root of 81684876 is about 433.8909096013.

The spelling of 81684876 in words is "eighty-one million, six hundred eighty-four thousand, eight hundred seventy-six".