4205421 has 24 divisors (see below), whose sum is σ = 6705504. Its totient is φ = 2518560.

The previous prime is 4205393. The next prime is 4205437. The reversal of 4205421 is 1245024.

It is not a de Polignac number, because 4205421 - 2¹¹ = 4203373 is a prime.

It is an Ulam number.

4205421 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4205394 and 4205403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4205321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10395 + ... + 10791.

It is an arithmetic number, because the mean of its divisors is an integer number (279396).

Almost surely, 2^4205421 is an apocalyptic number.

It is an amenable number.

4205421 is a deficient number, since it is larger than the sum of its proper divisors (2500083).

4205421 is a wasteful number, since it uses less digits than its factorization.

4205421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 518 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 4205421 is about 2050.7123152700. The cubic root of 4205421 is about 161.4122506053.

The spelling of 4205421 in words is "four million, two hundred five thousand, four hundred twenty-one".