172891669 has 2 divisors, whose sum is σ = 172891670. Its totient is φ = 172891668.

The previous prime is 172891657. The next prime is 172891687. The reversal of 172891669 is 966198271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171950769 + 940900 = 13113^2 + 970^2 .

It is an emirp because it is prime and its reverse (966198271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172891669 - 2⁵ = 172891637 is a prime.

It is a super-2 number, since 2×172891669² = 59783058419211122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172891969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86445834 + 86445835.

It is an arithmetic number, because the mean of its divisors is an integer number (86445835).

Almost surely, 2^172891669 is an apocalyptic number.

It is an amenable number.

172891669 is a deficient number, since it is larger than the sum of its proper divisors (1).

172891669 is an equidigital number, since it uses as much as digits as its factorization.

172891669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 49.

The square root of 172891669 is about 13148.8276663739. The cubic root of 172891669 is about 557.0891356329.

The spelling of 172891669 in words is "one hundred seventy-two million, eight hundred ninety-one thousand, six hundred sixty-nine".