172117845 has 32 divisors (see below), whose sum is σ = 310314240. Its totient is φ = 90498240.

The previous prime is 172117831. The next prime is 172117849. The reversal of 172117845 is 548711271.

It is not a de Polignac number, because 172117845 - 2¹² = 172113749 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172117849) 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 in 31 ways as a sum of consecutive naturals, for example, 607 + ... + 18563.

It is an arithmetic number, because the mean of its divisors is an integer number (9697320).

Almost surely, 2^172117845 is an apocalyptic number.

172117845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

172117845 is a deficient number, since it is larger than the sum of its proper divisors (138196395).

172117845 is a wasteful number, since it uses less digits than its factorization.

172117845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18042 (or 18036 counting only the distinct ones).

The product of its digits is 15680, while the sum is 36.

The square root of 172117845 is about 13119.3690778177. The cubic root of 172117845 is about 556.2567575664.

The spelling of 172117845 in words is "one hundred seventy-two million, one hundred seventeen thousand, eight hundred forty-five".