16685982881 has 4 divisors (see below), whose sum is σ = 16687103664. Its totient is φ = 16684862100.

The previous prime is 16685982877. The next prime is 16685982889. The reversal of 16685982881 is 18828958661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16685982881 - 2² = 16685982877 is a prime.

It is a super-2 number, since 2×16685982881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16685982889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 537755 + ... + 567936.

It is an arithmetic number, because the mean of its divisors is an integer number (4171775916).

Almost surely, 2^16685982881 is an apocalyptic number.

It is an amenable number.

16685982881 is a deficient number, since it is larger than the sum of its proper divisors (1120783).

16685982881 is a wasteful number, since it uses less digits than its factorization.

16685982881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120782.

The product of its digits is 13271040, while the sum is 62.

The spelling of 16685982881 in words is "sixteen billion, six hundred eighty-five million, nine hundred eighty-two thousand, eight hundred eighty-one".