3958639 has 4 divisors (see below), whose sum is σ = 3966424. Its totient is φ = 3950856.

The previous prime is 3958627. The next prime is 3958657. The reversal of 3958639 is 9368593.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9368593 = 13 ⋅720661.

It is a cyclic number.

It is not a de Polignac number, because 3958639 - 2¹⁹ = 3434351 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3958595 and 3958604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3958039) 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, 3072 + ... + 4165.

It is an arithmetic number, because the mean of its divisors is an integer number (991606).

Almost surely, 2^3958639 is an apocalyptic number.

3958639 is a deficient number, since it is larger than the sum of its proper divisors (7785).

3958639 is an equidigital number, since it uses as much as digits as its factorization.

3958639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7784.

The product of its digits is 174960, while the sum is 43.

The square root of 3958639 is about 1989.6328807094. The cubic root of 3958639 is about 158.1910709846.

The spelling of 3958639 in words is "three million, nine hundred fifty-eight thousand, six hundred thirty-nine".