20815706113 has 2 divisors, whose sum is σ = 20815706114. Its totient is φ = 20815706112.

The previous prime is 20815706099. The next prime is 20815706147. The reversal of 20815706113 is 31160751802.

It is a happy number.

It is an a-pointer prime, because the next prime (20815706147) can be obtained adding 20815706113 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15320745729 + 5494960384 = 123777^2 + 74128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20815706113 is a prime.

It is not a weakly prime, because it can be changed into another prime (20815706713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10407853056 + 10407853057.

It is an arithmetic number, because the mean of its divisors is an integer number (10407853057).

Almost surely, 2^20815706113 is an apocalyptic number.

It is an amenable number.

20815706113 is a deficient number, since it is larger than the sum of its proper divisors (1).

20815706113 is an equidigital number, since it uses as much as digits as its factorization.

20815706113 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The spelling of 20815706113 in words is "twenty billion, eight hundred fifteen million, seven hundred six thousand, one hundred thirteen".