20413525516621 has 2 divisors, whose sum is σ = 20413525516622. Its totient is φ = 20413525516620.

The previous prime is 20413525516609. The next prime is 20413525516673. The reversal of 20413525516621 is 12661552531402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20307956409225 + 105569107396 = 4506435^2 + 324914^2 .

It is a cyclic number.

It is not a de Polignac number, because 20413525516621 - 2²⁷ = 20413391298893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20413525516921) 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, 10206762758310 + 10206762758311.

It is an arithmetic number, because the mean of its divisors is an integer number (10206762758311).

Almost surely, 2^{20413525516621} is an apocalyptic number.

It is an amenable number.

20413525516621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20413525516621 is an equidigital number, since it uses as much as digits as its factorization.

20413525516621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432000, while the sum is 43.

The spelling of 20413525516621 in words is "twenty trillion, four hundred thirteen billion, five hundred twenty-five million, five hundred sixteen thousand, six hundred twenty-one".