20355012521171 has 2 divisors, whose sum is σ = 20355012521172. Its totient is φ = 20355012521170.

The previous prime is 20355012521167. The next prime is 20355012521183. The reversal of 20355012521171 is 17112521055302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20355012521171 - 2² = 20355012521167 is a prime.

It is a super-2 number, since 2×20355012521171² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20355012521141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10177506260585 + 10177506260586.

It is an arithmetic number, because the mean of its divisors is an integer number (10177506260586).

Almost surely, 2^{20355012521171} is an apocalyptic number.

20355012521171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20355012521171 is an equidigital number, since it uses as much as digits as its factorization.

20355012521171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21000, while the sum is 35.

Adding to 20355012521171 its reverse (17112521055302), we get a palindrome (37467533576473).

The spelling of 20355012521171 in words is "twenty trillion, three hundred fifty-five billion, twelve million, five hundred twenty-one thousand, one hundred seventy-one".