3906421 has 4 divisors (see below), whose sum is σ = 3997312. Its totient is φ = 3815532.

The previous prime is 3906407. The next prime is 3906431. The reversal of 3906421 is 1246093.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3906421 - 2⁷ = 3906293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3906401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45381 + ... + 45466.

It is an arithmetic number, because the mean of its divisors is an integer number (999328).

Almost surely, 2^3906421 is an apocalyptic number.

It is an amenable number.

3906421 is a deficient number, since it is larger than the sum of its proper divisors (90891).

3906421 is an equidigital number, since it uses as much as digits as its factorization.

3906421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90890.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 3906421 is about 1976.4667970902. The cubic root of 3906421 is about 157.4924292993.

The spelling of 3906421 in words is "three million, nine hundred six thousand, four hundred twenty-one".