171311220 has 192 divisors, whose sum is σ = 572544000. Its totient is φ = 42394752.

The previous prime is 171311213. The next prime is 171311249. The reversal of 171311220 is 22113171.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 171311193 and 171311202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 605199 + ... + 605481.

It is an arithmetic number, because the mean of its divisors is an integer number (2982000).

Almost surely, 2^171311220 is an apocalyptic number.

171311220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 171311220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286272000).

171311220 is an abundant number, since it is smaller than the sum of its proper divisors (401232780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

171311220 is a wasteful number, since it uses less digits than its factorization.

171311220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 18.

The square root of 171311220 is about 13088.5912152531. The cubic root of 171311220 is about 555.3864364933.

Adding to 171311220 its reverse (22113171), we get a palindrome (193424391).

The spelling of 171311220 in words is "one hundred seventy-one million, three hundred eleven thousand, two hundred twenty".