81779046686 has 8 divisors (see below), whose sum is σ = 129884368320. Its totient is φ = 38484257248.

The previous prime is 81779046673. The next prime is 81779046697. The reversal of 81779046686 is 68664097718.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1202633006 + ... + 1202633073.

It is an arithmetic number, because the mean of its divisors is an integer number (16235546040).

Almost surely, 2^81779046686 is an apocalyptic number.

81779046686 is a deficient number, since it is larger than the sum of its proper divisors (48105321634).

81779046686 is a wasteful number, since it uses less digits than its factorization.

81779046686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2405266098.

The product of its (nonzero) digits is 24385536, while the sum is 62.

The spelling of 81779046686 in words is "eighty-one billion, seven hundred seventy-nine million, forty-six thousand, six hundred eighty-six".