20136471156721 has 2 divisors, whose sum is σ = 20136471156722. Its totient is φ = 20136471156720.

The previous prime is 20136471156629. The next prime is 20136471156749. The reversal of 20136471156721 is 12765117463102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17168086746721 + 2968384410000 = 4143439^2 + 1722900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20136471156721 - 2³³ = 20127881222129 is a prime.

It is not a weakly prime, because it can be changed into another prime (20136411156721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10068235578360 + 10068235578361.

It is an arithmetic number, because the mean of its divisors is an integer number (10068235578361).

Almost surely, 2^{20136471156721} is an apocalyptic number.

It is an amenable number.

20136471156721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20136471156721 is an equidigital number, since it uses as much as digits as its factorization.

20136471156721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 20136471156721 in words is "twenty trillion, one hundred thirty-six billion, four hundred seventy-one million, one hundred fifty-six thousand, seven hundred twenty-one".