1722320 has 20 divisors (see below), whose sum is σ = 4004580. Its totient is φ = 688896.

The previous prime is 1722319. The next prime is 1722323. The reversal of 1722320 is 232271.

It can be written as a sum of positive squares in 2 ways, for example, as 440896 + 1281424 = 664^2 + 1132^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1722323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10685 + ... + 10844.

It is an arithmetic number, because the mean of its divisors is an integer number (200229).

2^1722320 is an apocalyptic number.

1722320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1722320 is an abundant number, since it is smaller than the sum of its proper divisors (2282260).

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

1722320 is a wasteful number, since it uses less digits than its factorization.

1722320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21542 (or 21536 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 1722320 is about 1312.3718985105. The cubic root of 1722320 is about 119.8683741934.

Adding to 1722320 its reverse (232271), we get a palindrome (1954591).

The spelling of 1722320 in words is "one million, seven hundred twenty-two thousand, three hundred twenty".