16989259970809 has 81 divisors (see below), whose sum is σ = 22169190744207. Its totient is φ = 12977150514048.

The previous prime is 16989259970807. The next prime is 16989259970821. The reversal of 16989259970809 is 90807995298961.

The square root of 16989259970809 is 4121803.

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

It can be written as a sum of positive squares in only one way, i.e., 13226932503225 + 3762327467584 = 3636885^2 + 1939672^2 .

It is not a de Polignac number, because 16989259970809 - 2¹ = 16989259970807 is a prime.

It is a super-2 number, since 2×16989259970809² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16989259970803) 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, 9319395672 + ... + 9319397494.

Almost surely, 2^{16989259970809} is an apocalyptic number.

16989259970809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

16989259970809 is the 4121803-rd square number.

16989259970809 is the 2060902-nd centered octagonal number.

It is an amenable number.

16989259970809 is a deficient number, since it is larger than the sum of its proper divisors (5179930773398).

16989259970809 is an frugal number, since it uses more digits than its factorization.

16989259970809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732 (or 1866 counting only the distinct ones).

The product of its (nonzero) digits is 1587237120, while the sum is 82.

The spelling of 16989259970809 in words is "sixteen trillion, nine hundred eighty-nine billion, two hundred fifty-nine million, nine hundred seventy thousand, eight hundred nine".