20910805913 has 2 divisors, whose sum is σ = 20910805914. Its totient is φ = 20910805912.

The previous prime is 20910805897. The next prime is 20910805921. The reversal of 20910805913 is 31950801902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11939495824 + 8971310089 = 109268^2 + 94717^2 .

It is a cyclic number.

It is not a de Polignac number, because 20910805913 - 2⁴ = 20910805897 is a prime.

It is not a weakly prime, because it can be changed into another prime (20910825913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10455402956 + 10455402957.

It is an arithmetic number, because the mean of its divisors is an integer number (10455402957).

Almost surely, 2^20910805913 is an apocalyptic number.

It is an amenable number.

20910805913 is a deficient number, since it is larger than the sum of its proper divisors (1).

20910805913 is an equidigital number, since it uses as much as digits as its factorization.

20910805913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 20910805913 in words is "twenty billion, nine hundred ten million, eight hundred five thousand, nine hundred thirteen".