16658668378781 has 16 divisors (see below), whose sum is σ = 19764795512448. Its totient is φ = 13840893192000.

The previous prime is 16658668378739. The next prime is 16658668378783. The reversal of 16658668378781 is 18787386685661.

16658668378781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16658668378781 is a prime.

It is a super-2 number, since 2×16658668378781² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16658668378696 and 16658668378705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16658668378783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 576689441 + ... + 576718326.

It is an arithmetic number, because the mean of its divisors is an integer number (1235299719528).

Almost surely, 2^{16658668378781} is an apocalyptic number.

16658668378781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16658668378781 is a deficient number, since it is larger than the sum of its proper divisors (3106127133667).

16658668378781 is a wasteful number, since it uses less digits than its factorization.

16658668378781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153407892.

The product of its digits is 3901685760, while the sum is 80.

The spelling of 16658668378781 in words is "sixteen trillion, six hundred fifty-eight billion, six hundred sixty-eight million, three hundred seventy-eight thousand, seven hundred eighty-one".