81668382 has 8 divisors (see below), whose sum is σ = 163336776. Its totient is φ = 27222792.

The previous prime is 81668381. The next prime is 81668387. The reversal of 81668382 is 28386618.

It is a sphenic number, since it is the product of 3 distinct primes.

81668382 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81668381) 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, 6805693 + ... + 6805704.

It is an arithmetic number, because the mean of its divisors is an integer number (20417097).

Almost surely, 2^81668382 is an apocalyptic number.

81668382 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81668382 is a wasteful number, since it uses less digits than its factorization.

81668382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13611402.

The product of its digits is 110592, while the sum is 42.

The square root of 81668382 is about 9037.0560471870. The cubic root of 81668382 is about 433.8617035484.

The spelling of 81668382 in words is "eighty-one million, six hundred sixty-eight thousand, three hundred eighty-two".