81091982 has 8 divisors (see below), whose sum is σ = 122310552. Its totient is φ = 40321800.

The previous prime is 81091979. The next prime is 81091993. The reversal of 81091982 is 28919018.

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, 111644 + ... + 112367.

It is an arithmetic number, because the mean of its divisors is an integer number (15288819).

Almost surely, 2^81091982 is an apocalyptic number.

81091982 is a deficient number, since it is larger than the sum of its proper divisors (41218570).

81091982 is a wasteful number, since it uses less digits than its factorization.

81091982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224194.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 81091982 is about 9005.1086611989. The cubic root of 81091982 is about 432.8385881489.

The spelling of 81091982 in words is "eighty-one million, ninety-one thousand, nine hundred eighty-two".