21003122171 has 2 divisors, whose sum is σ = 21003122172. Its totient is φ = 21003122170.

The previous prime is 21003122159. The next prime is 21003122183. The reversal of 21003122171 is 17122130012.

It is a balanced prime because it is at equal distance from previous prime (21003122159) and next prime (21003122183).

It is a cyclic number.

It is not a de Polignac number, because 21003122171 - 2¹⁸ = 21002860027 is a prime.

It is a super-2 number, since 2×21003122171² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003112171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501561085 + 10501561086.

It is an arithmetic number, because the mean of its divisors is an integer number (10501561086).

Almost surely, 2^21003122171 is an apocalyptic number.

21003122171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003122171 is an equidigital number, since it uses as much as digits as its factorization.

21003122171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21003122171 its reverse (17122130012), we get a palindrome (38125252183).

The spelling of 21003122171 in words is "twenty-one billion, three million, one hundred twenty-two thousand, one hundred seventy-one".