3806405 has 8 divisors (see below), whose sum is σ = 4608792. Its totient is φ = 3017728.

The previous prime is 3806347. The next prime is 3806423. The reversal of 3806405 is 5046083.

3806405 = T₂₀₁ + T₂₀₂ + ... + T₃₁₃.

It can be written as a sum of positive squares in 4 ways, for example, as 4 + 3806401 = 2^2 + 1951^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3806405 - 2²⁰ = 2757829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2804 + ... + 3933.

It is an arithmetic number, because the mean of its divisors is an integer number (576099).

Almost surely, 2^3806405 is an apocalyptic number.

It is an amenable number.

3806405 is a deficient number, since it is larger than the sum of its proper divisors (802387).

3806405 is a wasteful number, since it uses less digits than its factorization.

3806405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6855.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 3806405 is about 1951.0010251151. The cubic root of 3806405 is about 156.1367007983.

The spelling of 3806405 in words is "three million, eight hundred six thousand, four hundred five".