3890405 has 4 divisors (see below), whose sum is σ = 4668492. Its totient is φ = 3112320.

The previous prime is 3890387. The next prime is 3890417. The reversal of 3890405 is 5040983.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5040983 = 29 ⋅173827.

It can be written as a sum of positive squares in 2 ways, for example, as 1682209 + 2208196 = 1297^2 + 1486^2 .

It is not a de Polignac number, because 3890405 - 2⁸ = 3890149 is a prime.

It is a Duffinian number.

It is a Curzon 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, 389036 + ... + 389045.

It is an arithmetic number, because the mean of its divisors is an integer number (1167123).

Almost surely, 2^3890405 is an apocalyptic number.

It is an amenable number.

3890405 is a deficient number, since it is larger than the sum of its proper divisors (778087).

3890405 is an equidigital number, since it uses as much as digits as its factorization.

3890405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778086.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 3890405 is about 1972.4109612350. The cubic root of 3890405 is about 157.2768992076.

The spelling of 3890405 in words is "three million, eight hundred ninety thousand, four hundred five".