20715520565449 has 2 divisors, whose sum is σ = 20715520565450. Its totient is φ = 20715520565448.

The previous prime is 20715520565407. The next prime is 20715520565557. The reversal of 20715520565449 is 94456502551702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20006548145424 + 708972420025 = 4472868^2 + 842005^2 .

It is a cyclic number.

It is not a de Polignac number, because 20715520565449 - 2⁷ = 20715520565321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20715520565449.

It is not a weakly prime, because it can be changed into another prime (20715550565449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10357760282724 + 10357760282725.

It is an arithmetic number, because the mean of its divisors is an integer number (10357760282725).

Almost surely, 2^{20715520565449} is an apocalyptic number.

It is an amenable number.

20715520565449 is a deficient number, since it is larger than the sum of its proper divisors (1).

20715520565449 is an equidigital number, since it uses as much as digits as its factorization.

20715520565449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120000, while the sum is 55.

The spelling of 20715520565449 in words is "twenty trillion, seven hundred fifteen billion, five hundred twenty million, five hundred sixty-five thousand, four hundred forty-nine".