16686120721281 has 64 divisors (see below), whose sum is σ = 25195017019392. Its totient is φ = 9731479680000.

The previous prime is 16686120721279. The next prime is 16686120721367. The reversal of 16686120721281 is 18212702168661.

It is a happy number.

It is not a de Polignac number, because 16686120721281 - 2¹ = 16686120721279 is a prime.

It is a super-2 number, since 2×16686120721281² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16686120721981) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 166859626 + ... + 166959596.

It is an arithmetic number, because the mean of its divisors is an integer number (393672140928).

Almost surely, 2^{16686120721281} is an apocalyptic number.

16686120721281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16686120721281 is a deficient number, since it is larger than the sum of its proper divisors (8508896298111).

16686120721281 is a wasteful number, since it uses less digits than its factorization.

16686120721281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100934.

The product of its (nonzero) digits is 774144, while the sum is 51.

The spelling of 16686120721281 in words is "sixteen trillion, six hundred eighty-six billion, one hundred twenty million, seven hundred twenty-one thousand, two hundred eighty-one".