172821432 has 96 divisors (see below), whose sum is σ = 505612800. Its totient is φ = 49081536.

The previous prime is 172821421. The next prime is 172821433. The reversal of 172821432 is 234128271.

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

It is a self number, because there is not a number n which added to its sum of digits gives 172821432.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172821433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 261919 + ... + 262577.

It is an arithmetic number, because the mean of its divisors is an integer number (5266800).

Almost surely, 2^172821432 is an apocalyptic number.

172821432 is a gapful number since it is divisible by the number (12) 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 172821432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252806400).

172821432 is an abundant number, since it is smaller than the sum of its proper divisors (332791368).

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

172821432 is a wasteful number, since it uses less digits than its factorization.

172821432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905 (or 894 counting only the distinct ones).

The product of its digits is 5376, while the sum is 30.

The square root of 172821432 is about 13146.1565485886. The cubic root of 172821432 is about 557.0136865195.

The spelling of 172821432 in words is "one hundred seventy-two million, eight hundred twenty-one thousand, four hundred thirty-two".