4391421 has 16 divisors (see below), whose sum is σ = 6065280. Its totient is φ = 2824640.

The previous prime is 4391417. The next prime is 4391437. The reversal of 4391421 is 1241934.

4391421 is an esthetic number in base 13, because in such base its adjacent digits differ by 1.

It is a cyclic number.

It is not a de Polignac number, because 4391421 - 2² = 4391417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4391391 and 4391400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4391411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11095 + ... + 11483.

It is an arithmetic number, because the mean of its divisors is an integer number (379080).

Almost surely, 2^4391421 is an apocalyptic number.

It is an amenable number.

4391421 is a deficient number, since it is larger than the sum of its proper divisors (1673859).

4391421 is a wasteful number, since it uses less digits than its factorization.

4391421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516.

The product of its digits is 864, while the sum is 24.

The square root of 4391421 is about 2095.5717596876. The cubic root of 4391421 is about 163.7576854773.

The spelling of 4391421 in words is "four million, three hundred ninety-one thousand, four hundred twenty-one".