171889404845 has 16 divisors (see below), whose sum is σ = 207397877808. Its totient is φ = 136759311360.

The previous prime is 171889404773. The next prime is 171889404847. The reversal of 171889404845 is 548404988171.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 38438739364 + 133450665481 = 196058^2 + 365309^2 .

It is a de Polignac number, because none of the positive numbers 2^k-171889404845 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171889404847) 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, 817967 + ... + 1006403.

It is an arithmetic number, because the mean of its divisors is an integer number (12962367363).

Almost surely, 2^171889404845 is an apocalyptic number.

It is an amenable number.

171889404845 is a deficient number, since it is larger than the sum of its proper divisors (35508472963).

171889404845 is a wasteful number, since it uses less digits than its factorization.

171889404845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189440.

The product of its (nonzero) digits is 10321920, while the sum is 59.

The spelling of 171889404845 in words is "one hundred seventy-one billion, eight hundred eighty-nine million, four hundred four thousand, eight hundred forty-five".