171888206208545 has 16 divisors (see below), whose sum is σ = 207660571635600. Its totient is φ = 136580841196800.

The previous prime is 171888206208541. The next prime is 171888206208559. The reversal of 171888206208545 is 545802602888171.

It can be written as a sum of positive squares in 8 ways, for example, as 44361687448849 + 127526518759696 = 6660457^2 + 11292764^2 .

It is not a de Polignac number, because 171888206208545 - 2² = 171888206208541 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (171888206208541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9153635 + ... + 20677655.

It is an arithmetic number, because the mean of its divisors is an integer number (12978785727225).

Almost surely, 2^{171888206208545} is an apocalyptic number.

It is an amenable number.

171888206208545 is a deficient number, since it is larger than the sum of its proper divisors (35772365427055).

171888206208545 is a wasteful number, since it uses less digits than its factorization.

171888206208545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11544196.

The product of its (nonzero) digits is 68812800, while the sum is 65.

The spelling of 171888206208545 in words is "one hundred seventy-one trillion, eight hundred eighty-eight billion, two hundred six million, two hundred eight thousand, five hundred forty-five".