2172321 has 12 divisors (see below), whose sum is σ = 3191760. Its totient is φ = 1423320.

The previous prime is 2172283. The next prime is 2172323. The reversal of 2172321 is 1232712.

It is not a de Polignac number, because 2172321 - 2⁶ = 2172257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2172294 and 2172303.

It is not an unprimeable number, because it can be changed into a prime (2172323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1515 + ... + 2576.

It is an arithmetic number, because the mean of its divisors is an integer number (265980).

2^2172321 is an apocalyptic number.

It is an amenable number.

2172321 is a deficient number, since it is larger than the sum of its proper divisors (1019439).

2172321 is a wasteful number, since it uses less digits than its factorization.

2172321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4156 (or 4153 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 2172321 is about 1473.8795744565. The cubic root of 2172321 is about 129.5114006351.

The spelling of 2172321 in words is "two million, one hundred seventy-two thousand, three hundred twenty-one".