81702558921 has 8 divisors (see below), whose sum is σ = 108976384000. Its totient is φ = 54448553232.

The previous prime is 81702558907. The next prime is 81702558941. The reversal of 81702558921 is 12985520718.

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

It is not a de Polignac number, because 81702558921 - 2¹⁰ = 81702557897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81702558941) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 4945225 + ... + 4961718.

It is an arithmetic number, because the mean of its divisors is an integer number (13622048000).

Almost surely, 2^81702558921 is an apocalyptic number.

It is an amenable number.

81702558921 is a deficient number, since it is larger than the sum of its proper divisors (27273825079).

81702558921 is a wasteful number, since it uses less digits than its factorization.

81702558921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9909695.

The product of its (nonzero) digits is 403200, while the sum is 48.

The spelling of 81702558921 in words is "eighty-one billion, seven hundred two million, five hundred fifty-eight thousand, nine hundred twenty-one".