2172421 has 8 divisors (see below), whose sum is σ = 2229120. Its totient is φ = 2116608.

The previous prime is 2172397. The next prime is 2172427. The reversal of 2172421 is 1242712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2172421 - 2⁵ = 2172389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8325 + ... + 8581.

It is an arithmetic number, because the mean of its divisors is an integer number (278640).

2^2172421 is an apocalyptic number.

It is an amenable number.

2172421 is a deficient number, since it is larger than the sum of its proper divisors (56699).

2172421 is a wasteful number, since it uses less digits than its factorization.

2172421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443.

The product of its digits is 224, while the sum is 19.

The square root of 2172421 is about 1473.9134981402. The cubic root of 2172421 is about 129.5133879015.

The spelling of 2172421 in words is "two million, one hundred seventy-two thousand, four hundred twenty-one".