4243639 has 2 divisors, whose sum is σ = 4243640. Its totient is φ = 4243638.

The previous prime is 4243633. The next prime is 4243649. The reversal of 4243639 is 9363424.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4243639 - 2⁵ = 4243607 is a prime.

It is a d-powerful number, because it can be written as 4³ + 2¹¹ + 4¹¹ + 3⁹ + 6⁵ + 3⁹ + 9² .

It is a self number, because there is not a number n which added to its sum of digits gives 4243639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4243633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2121819 + 2121820.

It is an arithmetic number, because the mean of its divisors is an integer number (2121820).

Almost surely, 2^4243639 is an apocalyptic number.

4243639 is a deficient number, since it is larger than the sum of its proper divisors (1).

4243639 is an equidigital number, since it uses as much as digits as its factorization.

4243639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 31.

The square root of 4243639 is about 2060.0094659977. The cubic root of 4243639 is about 161.8997372788.

It can be divided in two parts, 42 and 43639, that added together give a square (43681 = 209²).

The spelling of 4243639 in words is "four million, two hundred forty-three thousand, six hundred thirty-nine".