81858321305 has 8 divisors (see below), whose sum is σ = 99413479872. Its totient is φ = 64697660848.

The previous prime is 81858321287. The next prime is 81858321323. The reversal of 81858321305 is 50312385818.

It is an interprime number because it is at equal distance from previous prime (81858321287) and next prime (81858321323).

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

It is a cyclic number.

It is not a de Polignac number, because 81858321305 - 2⁶ = 81858321241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98624069 + ... + 98624898.

It is an arithmetic number, because the mean of its divisors is an integer number (12426684984).

Almost surely, 2^81858321305 is an apocalyptic number.

It is an amenable number.

81858321305 is a deficient number, since it is larger than the sum of its proper divisors (17555158567).

81858321305 is a wasteful number, since it uses less digits than its factorization.

81858321305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197249055.

The product of its (nonzero) digits is 230400, while the sum is 44.

The spelling of 81858321305 in words is "eighty-one billion, eight hundred fifty-eight million, three hundred twenty-one thousand, three hundred five".