3949639 has 4 divisors (see below), whose sum is σ = 4056424. Its totient is φ = 3842856.

The previous prime is 3949619. The next prime is 3949643. The reversal of 3949639 is 9369493.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9369493 = 7 ⋅1338499.

It is a cyclic number.

It is not a de Polignac number, because 3949639 - 2¹¹ = 3947591 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3949595 and 3949604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3949609) 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, 53337 + ... + 53410.

It is an arithmetic number, because the mean of its divisors is an integer number (1014106).

Almost surely, 2^3949639 is an apocalyptic number.

3949639 is a deficient number, since it is larger than the sum of its proper divisors (106785).

3949639 is a wasteful number, since it uses less digits than its factorization.

3949639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106784.

The product of its digits is 157464, while the sum is 43.

The square root of 3949639 is about 1987.3698699538. The cubic root of 3949639 is about 158.0710970954.

The spelling of 3949639 in words is "three million, nine hundred forty-nine thousand, six hundred thirty-nine".