171221860 has 24 divisors (see below), whose sum is σ = 361985400. Its totient is φ = 68027904.

The previous prime is 171221857. The next prime is 171221879. The reversal of 171221860 is 68122171.

It can be written as a sum of positive squares in 4 ways, for example, as 8608356 + 162613504 = 2934^2 + 12752^2 .

It is a super-4 number, since 4×171221860⁴ (a number of 34 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25749 + ... + 31708.

It is an arithmetic number, because the mean of its divisors is an integer number (15082725).

Almost surely, 2^171221860 is an apocalyptic number.

171221860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

171221860 is an abundant number, since it is smaller than the sum of its proper divisors (190763540).

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

171221860 is a wasteful number, since it uses less digits than its factorization.

171221860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57615 (or 57613 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 171221860 is about 13085.1771099974. The cubic root of 171221860 is about 555.2898521137.

The spelling of 171221860 in words is "one hundred seventy-one million, two hundred twenty-one thousand, eight hundred sixty".