3969405 has 54 divisors (see below), whose sum is σ = 7853118. Its totient is φ = 1924560.

The previous prime is 3969391. The next prime is 3969419. The reversal of 3969405 is 5049693.

It is an interprime number because it is at equal distance from previous prime (3969391) and next prime (3969419).

It can be written as a sum of positive squares in only one way, i.e., 3175524 + 793881 = 1782^2 + 891^2 .

It is not a de Polignac number, because 3969405 - 2⁴ = 3969389 is a prime.

It is a Curzon number.

It is a nialpdrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 3969405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 360850 + ... + 360860.

Almost surely, 2^3969405 is an apocalyptic number.

It is an amenable number.

3969405 is a deficient number, since it is larger than the sum of its proper divisors (3883713).

3969405 is an frugal number, since it uses more digits than its factorization.

3969405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 19 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 3969405 is about 1992.3365679523. The cubic root of 3969405 is about 158.3343477928.

It can be divided in two parts, 396 and 9405, that added together give a square (9801 = 99²).

The spelling of 3969405 in words is "three million, nine hundred sixty-nine thousand, four hundred five".