18660001661663 has 8 divisors (see below), whose sum is σ = 19262093723136. Its totient is φ = 18057919383000.

The previous prime is 18660001661659. The next prime is 18660001661689. The reversal of 18660001661663 is 36616610006681.

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 18660001661663 - 2² = 18660001661659 is a prime.

It is a super-2 number, since 2×18660001661663² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18660001661963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1533488 + ... + 6298538.

It is an arithmetic number, because the mean of its divisors is an integer number (2407761715392).

Almost surely, 2^{18660001661663} is an apocalyptic number.

18660001661663 is a deficient number, since it is larger than the sum of its proper divisors (602092061473).

18660001661663 is a wasteful number, since it uses less digits than its factorization.

18660001661663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4891405.

The product of its (nonzero) digits is 1119744, while the sum is 50.

The spelling of 18660001661663 in words is "eighteen trillion, six hundred sixty billion, one million, six hundred sixty-one thousand, six hundred sixty-three".