20516521241 has 2 divisors, whose sum is σ = 20516521242. Its totient is φ = 20516521240.

The previous prime is 20516521219. The next prime is 20516521253. The reversal of 20516521241 is 14212561502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10651065616 + 9865455625 = 103204^2 + 99325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20516521241 is a prime.

It is not a weakly prime, because it can be changed into another prime (20516521741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258260620 + 10258260621.

It is an arithmetic number, because the mean of its divisors is an integer number (10258260621).

Almost surely, 2^20516521241 is an apocalyptic number.

It is an amenable number.

20516521241 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516521241 is an equidigital number, since it uses as much as digits as its factorization.

20516521241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4800, while the sum is 29.

The spelling of 20516521241 in words is "twenty billion, five hundred sixteen million, five hundred twenty-one thousand, two hundred forty-one".