9172820 has 48 divisors (see below), whose sum is σ = 20563200. Its totient is φ = 3427200.

The previous prime is 9172817. The next prime is 9172831. The reversal of 9172820 is 282719.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38261 + ... + 38499.

It is an arithmetic number, because the mean of its divisors is an integer number (428400).

Almost surely, 2^9172820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9172820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10281600).

9172820 is an abundant number, since it is smaller than the sum of its proper divisors (11390380).

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

9172820 is a wasteful number, since it uses less digits than its factorization.

9172820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 9172820 is about 3028.6663731748. Note that the first 3 decimals coincide. The cubic root of 9172820 is about 209.3313578007.

It can be divided in two parts, 91 and 72820, that multiplied together give a triangular number (6626620 = T₃₆₄₀).

The spelling of 9172820 in words is "nine million, one hundred seventy-two thousand, eight hundred twenty".