170621272109 has 2 divisors, whose sum is σ = 170621272110. Its totient is φ = 170621272108.

The previous prime is 170621272099. The next prime is 170621272127. The reversal of 170621272109 is 901272126071.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139644216100 + 30977056009 = 373690^2 + 176003^2 .

It is a cyclic number.

It is not a de Polignac number, because 170621272109 - 2²⁰ = 170620223533 is a prime.

It is a super-2 number, since 2×170621272109² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (170621272609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85310636054 + 85310636055.

It is an arithmetic number, because the mean of its divisors is an integer number (85310636055).

Almost surely, 2^170621272109 is an apocalyptic number.

It is an amenable number.

170621272109 is a deficient number, since it is larger than the sum of its proper divisors (1).

170621272109 is an equidigital number, since it uses as much as digits as its factorization.

170621272109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 38.

The spelling of 170621272109 in words is "one hundred seventy billion, six hundred twenty-one million, two hundred seventy-two thousand, one hundred nine".