171671287270921 has 9 divisors (see below), whose sum is σ = 171891413002183. Its totient is φ = 171451443124840.

The previous prime is 171671287270909. The next prime is 171671287270937. The reversal of 171671287270921 is 129072782176171.

The square root of 171671287270921 is 13102339.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 46873343580921 + 124797943690000 = 6846411^2 + 11171300^2 .

It is not a de Polignac number, because 171671287270921 - 2⁹ = 171671287270409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 171671287270921.

It is not an unprimeable number, because it can be changed into a prime (171671287270321) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10757012340 + ... + 10757028298.

Almost surely, 2^{171671287270921} is an apocalyptic number.

171671287270921 is the 13102339-th square number.

171671287270921 is the 6551170-th centered octagonal number.

It is an amenable number.

171671287270921 is a deficient number, since it is larger than the sum of its proper divisors (220125731262).

171671287270921 is an frugal number, since it uses more digits than its factorization.

171671287270921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33560 (or 16780 counting only the distinct ones).

The product of its (nonzero) digits is 8297856, while the sum is 61.

The spelling of 171671287270921 in words is "one hundred seventy-one trillion, six hundred seventy-one billion, two hundred eighty-seven million, two hundred seventy thousand, nine hundred twenty-one".