81681058682 has 4 divisors (see below), whose sum is σ = 122521588026. Its totient is φ = 40840529340.

The previous prime is 81681058681. The next prime is 81681058733. The reversal of 81681058682 is 28685018618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 67143692641 + 14537366041 = 259121^2 + 120571^2 .

It is not an unprimeable number, because it can be changed into a prime (81681058681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20420264669 + ... + 20420264672.

Almost surely, 2^81681058682 is an apocalyptic number.

81681058682 is a deficient number, since it is larger than the sum of its proper divisors (40840529344).

81681058682 is a wasteful number, since it uses less digits than its factorization.

81681058682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40840529343.

The product of its (nonzero) digits is 1474560, while the sum is 53.

The spelling of 81681058682 in words is "eighty-one billion, six hundred eighty-one million, fifty-eight thousand, six hundred eighty-two".