7172321 has 4 divisors (see below), whose sum is σ = 7724052. Its totient is φ = 6620592.

The previous prime is 7172311. The next prime is 7172327. The reversal of 7172321 is 1232717.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1232717 = 113 ⋅10909.

It can be written as a sum of positive squares in 2 ways, for example, as 541696 + 6630625 = 736^2 + 2575^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7172321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7172327) 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, 275846 + ... + 275871.

It is an arithmetic number, because the mean of its divisors is an integer number (1931013).

Almost surely, 2^7172321 is an apocalyptic number.

It is an amenable number.

7172321 is a deficient number, since it is larger than the sum of its proper divisors (551731).

7172321 is a wasteful number, since it uses less digits than its factorization.

7172321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551730.

The product of its digits is 588, while the sum is 23.

The square root of 7172321 is about 2678.1189293980. The cubic root of 7172321 is about 192.8501167471.

The spelling of 7172321 in words is "seven million, one hundred seventy-two thousand, three hundred twenty-one".