172207728 has 320 divisors, whose sum is σ = 639959040. Its totient is φ = 43027200.

The previous prime is 172207723. The next prime is 172207729. The reversal of 172207728 is 827702271.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 172207692 and 172207701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172207723) 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 63 ways as a sum of consecutive naturals, for example, 1031101 + ... + 1031267.

It is an arithmetic number, because the mean of its divisors is an integer number (1999872).

Almost surely, 2^172207728 is an apocalyptic number.

172207728 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 172207728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319979520).

172207728 is an abundant number, since it is smaller than the sum of its proper divisors (467751312).

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

172207728 is a wasteful number, since it uses less digits than its factorization.

172207728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 172207728 is about 13122.7942146480. The cubic root of 172207728 is about 556.3535697735.

Adding to 172207728 its reverse (827702271), we get a palindrome (999909999).

The spelling of 172207728 in words is "one hundred seventy-two million, two hundred seven thousand, seven hundred twenty-eight".