3964405 has 4 divisors (see below), whose sum is σ = 4757292. Its totient is φ = 3171520.

The previous prime is 3964399. The next prime is 3964421. The reversal of 3964405 is 5044693.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5044693 = 149 ⋅33857.

It can be written as a sum of positive squares in 2 ways, for example, as 1461681 + 2502724 = 1209^2 + 1582^2 .

It is not a de Polignac number, because 3964405 - 2³ = 3964397 is a prime.

It is a Duffinian number.

3964405 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396436 + ... + 396445.

It is an arithmetic number, because the mean of its divisors is an integer number (1189323).

Almost surely, 2^3964405 is an apocalyptic number.

It is an amenable number.

3964405 is a deficient number, since it is larger than the sum of its proper divisors (792887).

3964405 is an equidigital number, since it uses as much as digits as its factorization.

3964405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792886.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 3964405 is about 1991.0813644851. The cubic root of 3964405 is about 158.2678387167.

It can be divided in two parts, 3 and 964405, that multiplied together give a triangular number (2893215 = T₂₄₀₅).

The spelling of 3964405 in words is "three million, nine hundred sixty-four thousand, four hundred five".