171020720 has 40 divisors (see below), whose sum is σ = 428212176. Its totient is φ = 63145728.

The previous prime is 171020699. The next prime is 171020737. The reversal of 171020720 is 27020171.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 171020692 and 171020701.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81182 + ... + 83261.

Almost surely, 2^171020720 is an apocalyptic number.

171020720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

171020720 is an abundant number, since it is smaller than the sum of its proper divisors (257191456).

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

171020720 is a wasteful number, since it uses less digits than its factorization.

171020720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164469 (or 164463 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 171020720 is about 13077.4890556253. The cubic root of 171020720 is about 555.0723277759.

Adding to 171020720 its reverse (27020171), we get a palindrome (198040891).

The spelling of 171020720 in words is "one hundred seventy-one million, twenty thousand, seven hundred twenty".