172689920 has 80 divisors (see below), whose sum is σ = 445987080. Its totient is φ = 63750144.

The previous prime is 172689889. The next prime is 172689941. The reversal of 172689920 is 29986271.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 132342016 + 40347904 = 11504^2 + 6352^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30686 + ... + 35874.

Almost surely, 2^172689920 is an apocalyptic number.

172689920 is a gapful number since it is divisible by the number (10) 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 172689920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (222993540).

172689920 is an abundant number, since it is smaller than the sum of its proper divisors (273297160).

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

172689920 is an equidigital number, since it uses as much as digits as its factorization.

172689920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5225 (or 5209 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 172689920 is about 13141.1536784257. The cubic root of 172689920 is about 556.8723603496.

The spelling of 172689920 in words is "one hundred seventy-two million, six hundred eighty-nine thousand, nine hundred twenty".