16665656661 has 32 divisors (see below), whose sum is σ = 25557012480. Its totient is φ = 10724954688.

The previous prime is 16665656653. The next prime is 16665656681.

16665656661 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 16665656661 - 2³ = 16665656653 is a prime.

It is a super-2 number, since 2×16665656661² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16665656598 and 16665656607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665656611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61195 + ... + 192551.

It is an arithmetic number, because the mean of its divisors is an integer number (798656640).

Almost surely, 2^16665656661 is an apocalyptic number.

It is an amenable number.

16665656661 is a deficient number, since it is larger than the sum of its proper divisors (8891355819).

16665656661 is a wasteful number, since it uses less digits than its factorization.

16665656661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131530 (or 131524 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 54.

The spelling of 16665656661 in words is "sixteen billion, six hundred sixty-five million, six hundred fifty-six thousand, six hundred sixty-one".