18501685001681 has 8 divisors (see below), whose sum is σ = 21873913302720. Its totient is φ = 15311739311568.

The previous prime is 18501685001663. The next prime is 18501685001731. The reversal of 18501685001681 is 18610058610581.

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

It is not a de Polignac number, because 18501685001681 - 2³⁴ = 18484505132497 is a prime.

It is a super-2 number, since 2×18501685001681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18501685081681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45570652511 + ... + 45570652916.

It is an arithmetic number, because the mean of its divisors is an integer number (2734239162840).

Almost surely, 2^{18501685001681} is an apocalyptic number.

It is an amenable number.

18501685001681 is a deficient number, since it is larger than the sum of its proper divisors (3372228301039).

18501685001681 is an equidigital number, since it uses as much as digits as its factorization.

18501685001681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91141305463.

The product of its (nonzero) digits is 460800, while the sum is 50.

The spelling of 18501685001681 in words is "eighteen trillion, five hundred one billion, six hundred eighty-five million, one thousand, six hundred eighty-one".