20440165709 has 2 divisors, whose sum is σ = 20440165710. Its totient is φ = 20440165708.

The previous prime is 20440165703. The next prime is 20440165723. The reversal of 20440165709 is 90756104402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20205769609 + 234396100 = 142147^2 + 15310^2 .

It is a cyclic number.

It is not a de Polignac number, because 20440165709 - 2⁸ = 20440165453 is a prime.

It is a super-2 number, since 2×20440165709² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20440165703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10220082854 + 10220082855.

It is an arithmetic number, because the mean of its divisors is an integer number (10220082855).

Almost surely, 2^20440165709 is an apocalyptic number.

It is an amenable number.

20440165709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440165709 is an equidigital number, since it uses as much as digits as its factorization.

20440165709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 38.

The spelling of 20440165709 in words is "twenty billion, four hundred forty million, one hundred sixty-five thousand, seven hundred nine".