171681669 has 6 divisors (see below), whose sum is σ = 247984646. Its totient is φ = 114454440.

The previous prime is 171681661. The next prime is 171681673. The reversal of 171681669 is 966186171.

It can be written as a sum of positive squares in only one way, i.e., 155376225 + 16305444 = 12465^2 + 4038^2 .

It is not a de Polignac number, because 171681669 - 2³ = 171681661 is a prime.

It is a super-2 number, since 2×171681669² = 58949190941251122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171681661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9537862 + ... + 9537879.

Almost surely, 2^171681669 is an apocalyptic number.

It is an amenable number.

171681669 is a deficient number, since it is larger than the sum of its proper divisors (76302977).

171681669 is a wasteful number, since it uses less digits than its factorization.

171681669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19075747 (or 19075744 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 171681669 is about 13102.7351724745. The cubic root of 171681669 is about 555.7864768927.

The spelling of 171681669 in words is "one hundred seventy-one million, six hundred eighty-one thousand, six hundred sixty-nine".