4390621 has 2 divisors, whose sum is σ = 4390622. Its totient is φ = 4390620.

The previous prime is 4390619. The next prime is 4390651. The reversal of 4390621 is 1260934.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2924100 + 1466521 = 1710^2 + 1211^2 .

It is a cyclic number.

It is not a de Polignac number, because 4390621 - 2¹ = 4390619 is a prime.

Together with 4390619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4390651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2195310 + 2195311.

It is an arithmetic number, because the mean of its divisors is an integer number (2195311).

Almost surely, 2^4390621 is an apocalyptic number.

It is an amenable number.

4390621 is a deficient number, since it is larger than the sum of its proper divisors (1).

4390621 is an equidigital number, since it uses as much as digits as its factorization.

4390621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 4390621 is about 2095.3808722998. The cubic root of 4390621 is about 163.7477407765.

It can be divided in two parts, 4 and 390621, that added together give a 8-th power (390625 = 5⁸).

The spelling of 4390621 in words is "four million, three hundred ninety thousand, six hundred twenty-one".