4218421 has 4 divisors (see below), whose sum is σ = 4225644. Its totient is φ = 4211200.

The previous prime is 4218413. The next prime is 4218439. The reversal of 4218421 is 1248124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2515396 + 1703025 = 1586^2 + 1305^2 .

It is a cyclic number.

It is not a de Polignac number, because 4218421 - 2³ = 4218413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4218392 and 4218401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4212421) 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, 2650 + ... + 3931.

It is an arithmetic number, because the mean of its divisors is an integer number (1056411).

Almost surely, 2^4218421 is an apocalyptic number.

It is an amenable number.

4218421 is a deficient number, since it is larger than the sum of its proper divisors (7223).

4218421 is an equidigital number, since it uses as much as digits as its factorization.

4218421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7222.

The product of its digits is 512, while the sum is 22.

The square root of 4218421 is about 2053.8794998733. The cubic root of 4218421 is about 161.5784012935.

The spelling of 4218421 in words is "four million, two hundred eighteen thousand, four hundred twenty-one".