81693684 has 36 divisors (see below), whose sum is σ = 214154304. Its totient is φ = 27230904.

The previous prime is 81693683. The next prime is 81693697. The reversal of 81693684 is 48639618.

81693684 is nontrivially palindromic in base 8.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81693683) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41052 + ... + 42995.

Almost surely, 2^81693684 is an apocalyptic number.

It is an amenable number.

81693684 is an abundant number, since it is smaller than the sum of its proper divisors (132460620).

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

81693684 is a wasteful number, since it uses less digits than its factorization.

81693684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84066 (or 84052 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 81693684 is about 9038.4558415694. The cubic root of 81693684 is about 433.9065043844.

The spelling of 81693684 in words is "eighty-one million, six hundred ninety-three thousand, six hundred eighty-four".