172745920 has 56 divisors (see below), whose sum is σ = 412595568. Its totient is φ = 68889600.

The previous prime is 172745917. The next prime is 172745927. The reversal of 172745920 is 29547271.

It is a self number, because there is not a number n which added to its sum of digits gives 172745920.

It is not an unprimeable number, because it can be changed into a prime (172745927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146935 + ... + 148105.

It is an arithmetic number, because the mean of its divisors is an integer number (7367778).

Almost surely, 2^172745920 is an apocalyptic number.

172745920 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 172745920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206297784).

172745920 is an abundant number, since it is smaller than the sum of its proper divisors (239849648).

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

172745920 is a wasteful number, since it uses less digits than its factorization.

172745920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1649 (or 1639 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 172745920 is about 13143.2842166637. The cubic root of 172745920 is about 556.9325481551.

The spelling of 172745920 in words is "one hundred seventy-two million, seven hundred forty-five thousand, nine hundred twenty".