81684344 has 32 divisors (see below), whose sum is σ = 184252800. Its totient is φ = 33164640.

The previous prime is 81684331. The next prime is 81684359. The reversal of 81684344 is 44348618.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 81684298 and 81684307.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37322 + ... + 39449.

It is an arithmetic number, because the mean of its divisors is an integer number (5757900).

Almost surely, 2^81684344 is an apocalyptic number.

It is an amenable number.

81684344 is an abundant number, since it is smaller than the sum of its proper divisors (102568456).

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

81684344 is a wasteful number, since it uses less digits than its factorization.

81684344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76803 (or 76799 counting only the distinct ones).

The product of its digits is 73728, while the sum is 38.

The square root of 81684344 is about 9037.9391456239. The cubic root of 81684344 is about 433.8899676461.

It can be divided in two parts, 81684 and 344, that added together give a palindrome (82028).

The spelling of 81684344 in words is "eighty-one million, six hundred eighty-four thousand, three hundred forty-four".