20665567061 has 8 divisors (see below), whose sum is σ = 21279300504. Its totient is φ = 20057057280.

The previous prime is 20665567031. The next prime is 20665567063. The reversal of 20665567061 is 16076556602.

It can be written as a sum of positive squares in 4 ways, for example, as 581292100 + 20084274961 = 24110^2 + 141719^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20665567061 - 2⁶ = 20665566997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20665567063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1297886 + ... + 1313711.

It is an arithmetic number, because the mean of its divisors is an integer number (2659912563).

Almost surely, 2^20665567061 is an apocalyptic number.

It is an amenable number.

20665567061 is a deficient number, since it is larger than the sum of its proper divisors (613733443).

20665567061 is a wasteful number, since it uses less digits than its factorization.

20665567061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611831.

The product of its (nonzero) digits is 453600, while the sum is 44.

The spelling of 20665567061 in words is "twenty billion, six hundred sixty-five million, five hundred sixty-seven thousand, sixty-one".