171216720 has 160 divisors (see below), whose sum is σ = 609008640. Its totient is φ = 44167680.

The previous prime is 171216679. The next prime is 171216743. The reversal of 171216720 is 27612171.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65682 + ... + 68238.

It is an arithmetic number, because the mean of its divisors is an integer number (3806304).

Almost surely, 2^171216720 is an apocalyptic number.

171216720 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 171216720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304504320).

171216720 is an abundant number, since it is smaller than the sum of its proper divisors (437791920).

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

171216720 is a wasteful number, since it uses less digits than its factorization.

171216720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2610 (or 2598 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The square root of 171216720 is about 13084.9807030809. The cubic root of 171216720 is about 555.2842955443.

Adding to 171216720 its reverse (27612171), we get a palindrome (198828891).

It can be divided in two parts, 1 and 71216720, that added together give a square (71216721 = 8439²).

The spelling of 171216720 in words is "one hundred seventy-one million, two hundred sixteen thousand, seven hundred twenty".