3969639 has 24 divisors (see below), whose sum is σ = 6070272. Its totient is φ = 2494800.

The previous prime is 3969629. The next prime is 3969649. The reversal of 3969639 is 9369693.

3969639 is a `hidden beast` number, since 3 + 9 + 6 + 9 + 639 = 666.

It is an interprime number because it is at equal distance from previous prime (3969629) and next prime (3969649).

It is not a de Polignac number, because 3969639 - 2²⁰ = 2921063 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3969594 and 3969603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3969629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26214 + ... + 26364.

It is an arithmetic number, because the mean of its divisors is an integer number (252928).

Almost surely, 2^3969639 is an apocalyptic number.

3969639 is a deficient number, since it is larger than the sum of its proper divisors (2100633).

3969639 is a wasteful number, since it uses less digits than its factorization.

3969639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307 (or 304 counting only the distinct ones).

The product of its digits is 236196, while the sum is 45.

The square root of 3969639 is about 1992.3952921045. The cubic root of 3969639 is about 158.3374590492.

The spelling of 3969639 in words is "three million, nine hundred sixty-nine thousand, six hundred thirty-nine".