3995639 has 2 divisors, whose sum is σ = 3995640. Its totient is φ = 3995638.

The previous prime is 3995633. The next prime is 3995647. The reversal of 3995639 is 9365993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3995639 - 2⁴ = 3995623 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3995639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3995633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1997819 + 1997820.

It is an arithmetic number, because the mean of its divisors is an integer number (1997820).

Almost surely, 2^3995639 is an apocalyptic number.

3995639 is a deficient number, since it is larger than the sum of its proper divisors (1).

3995639 is an equidigital number, since it uses as much as digits as its factorization.

3995639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 196830, while the sum is 44.

The square root of 3995639 is about 1998.9094526766. The cubic root of 3995639 is about 158.6823954191.

The spelling of 3995639 in words is "three million, nine hundred ninety-five thousand, six hundred thirty-nine".