20967908809 has 9 divisors (see below), whose sum is σ = 21219192327. Its totient is φ = 20719571664.

The previous prime is 20967908791. The next prime is 20967908881. The reversal of 20967908809 is 90880976902.

The square root of 20967908809 is 144803.

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., 4026283209 + 16941625600 = 63453^2 + 130160^2 .

It is not a de Polignac number, because 20967908809 - 2⁵ = 20967908777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20967903809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12886654 + ... + 12888280.

Almost surely, 2^20967908809 is an apocalyptic number.

20967908809 is the 144803-rd square number.

20967908809 is the 72402-nd centered octagonal number.

It is an amenable number.

20967908809 is a deficient number, since it is larger than the sum of its proper divisors (251283518).

20967908809 is an frugal number, since it uses more digits than its factorization.

20967908809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3432 (or 1716 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 58.

The spelling of 20967908809 in words is "twenty billion, nine hundred sixty-seven million, nine hundred eight thousand, eight hundred nine".