20961382405 has 12 divisors (see below), whose sum is σ = 25295160492. Its totient is φ = 16675296320.

The previous prime is 20961382357. The next prime is 20961382417. The reversal of 20961382405 is 50428316902.

It can be written as a sum of positive squares in 2 ways, for example, as 3510444001 + 17450938404 = 59249^2 + 132102^2 .

It is not a de Polignac number, because 20961382405 - 2⁹ = 20961381893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 94785 + ... + 225625.

It is an arithmetic number, because the mean of its divisors is an integer number (2107930041).

Almost surely, 2^20961382405 is an apocalyptic number.

It is an amenable number.

20961382405 is a deficient number, since it is larger than the sum of its proper divisors (4333778087).

20961382405 is an equidigital number, since it uses as much as digits as its factorization.

20961382405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131204 (or 131025 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 20961382405 in words is "twenty billion, nine hundred sixty-one million, three hundred eighty-two thousand, four hundred five".