3906505 has 4 divisors (see below), whose sum is σ = 4687812. Its totient is φ = 3125200.

The previous prime is 3906493. The next prime is 3906541. The reversal of 3906505 is 5056093.

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: 5056093 = 7 ⋅722299.

It can be written as a sum of positive squares in 2 ways, for example, as 491401 + 3415104 = 701^2 + 1848^2 .

It is not a de Polignac number, because 3906505 - 2⁵ = 3906473 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 3 ways as a sum of consecutive naturals, for example, 390646 + ... + 390655.

It is an arithmetic number, because the mean of its divisors is an integer number (1171953).

Almost surely, 2^3906505 is an apocalyptic number.

It is an amenable number.

3906505 is a deficient number, since it is larger than the sum of its proper divisors (781307).

3906505 is an equidigital number, since it uses as much as digits as its factorization.

3906505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781306.

The product of its (nonzero) digits is 4050, while the sum is 28.

The square root of 3906505 is about 1976.4880470167. The cubic root of 3906505 is about 157.4935581475.

The spelling of 3906505 in words is "three million, nine hundred six thousand, five hundred five".