171261220 has 72 divisors (see below), whose sum is σ = 406558656. Its totient is φ = 60458112.

The previous prime is 171261203. The next prime is 171261227. The reversal of 171261220 is 22162171.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 171261191 and 171261200.

It is not an unprimeable number, because it can be changed into a prime (171261227) 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 23 ways as a sum of consecutive naturals, for example, 76639 + ... + 78841.

It is an arithmetic number, because the mean of its divisors is an integer number (5646648).

Almost surely, 2^171261220 is an apocalyptic number.

171261220 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 171261220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203279328).

171261220 is an abundant number, since it is smaller than the sum of its proper divisors (235297436).

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

171261220 is a wasteful number, since it uses less digits than its factorization.

171261220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261 (or 2246 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 171261220 is about 13086.6810154447. The cubic root of 171261220 is about 555.3323983439.

The spelling of 171261220 in words is "one hundred seventy-one million, two hundred sixty-one thousand, two hundred twenty".