16669688619609 has 81 divisors (see below), whose sum is σ = 25752127496277. Its totient is φ = 10389325732272.

The previous prime is 16669688619599. The next prime is 16669688619629. The reversal of 16669688619609 is 90691688696661.

The square root of 16669688619609 is 4082853.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 16669688619609 - 2⁹ = 16669688619097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16669688619629) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 19315977112 + ... + 19315977974.

Almost surely, 2^{16669688619609} is an apocalyptic number.

16669688619609 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

16669688619609 is the 4082853-rd square number.

16669688619609 is the 2041427-th centered octagonal number.

It is an amenable number.

16669688619609 is a deficient number, since it is larger than the sum of its proper divisors (9082438876668).

16669688619609 is an frugal number, since it uses more digits than its factorization.

16669688619609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 2176782336, while the sum is 81.

The spelling of 16669688619609 in words is "sixteen trillion, six hundred sixty-nine billion, six hundred eighty-eight million, six hundred nineteen thousand, six hundred nine".