172787328 has 144 divisors (see below), whose sum is σ = 578580210. Its totient is φ = 49351680.

The previous prime is 172787317. The next prime is 172787353. The reversal of 172787328 is 823787271.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 105021504 + 67765824 = 10248^2 + 8232^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×172787328³ (a number of 26 digits) contains 333 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 54918 + ... + 57978.

Almost surely, 2^172787328 is an apocalyptic number.

172787328 is a gapful number since it is divisible by the number (18) 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 172787328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289290105).

172787328 is an abundant number, since it is smaller than the sum of its proper divisors (405792882).

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

172787328 is a wasteful number, since it uses less digits than its factorization.

172787328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3095 (or 3073 counting only the distinct ones).

The product of its digits is 263424, while the sum is 45.

The square root of 172787328 is about 13144.8593754365. The cubic root of 172787328 is about 556.9770443735.

The spelling of 172787328 in words is "one hundred seventy-two million, seven hundred eighty-seven thousand, three hundred twenty-eight".