81639182 has 8 divisors (see below), whose sum is σ = 126409152. Its totient is φ = 39502800.

The previous prime is 81639179. The next prime is 81639191. The reversal of 81639182 is 28193618.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 658319 + ... + 658442.

It is an arithmetic number, because the mean of its divisors is an integer number (15801144).

Almost surely, 2^81639182 is an apocalyptic number.

81639182 is a deficient number, since it is larger than the sum of its proper divisors (44769970).

81639182 is a wasteful number, since it uses less digits than its factorization.

81639182 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316794.

The product of its digits is 20736, while the sum is 38.

The square root of 81639182 is about 9035.4403323800. The cubic root of 81639182 is about 433.8099892391.

The spelling of 81639182 in words is "eighty-one million, six hundred thirty-nine thousand, one hundred eighty-two".