20510405205353 has 4 divisors (see below), whose sum is σ = 23440463091840. Its totient is φ = 17580347318868.

The previous prime is 20510405205337. The next prime is 20510405205391. The reversal of 20510405205353 is 35350250401502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20510405205353 - 2⁴ = 20510405205337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20510405205313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1465028943233 + ... + 1465028943246.

It is an arithmetic number, because the mean of its divisors is an integer number (5860115772960).

Almost surely, 2^{20510405205353} is an apocalyptic number.

It is an amenable number.

20510405205353 is a deficient number, since it is larger than the sum of its proper divisors (2930057886487).

20510405205353 is an equidigital number, since it uses as much as digits as its factorization.

20510405205353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2930057886486.

The product of its (nonzero) digits is 90000, while the sum is 35.

Adding to 20510405205353 its reverse (35350250401502), we get a palindrome (55860655606855).

The spelling of 20510405205353 in words is "twenty trillion, five hundred ten billion, four hundred five million, two hundred five thousand, three hundred fifty-three".