3921405 has 8 divisors (see below), whose sum is σ = 6274272. Its totient is φ = 2091408.

The previous prime is 3921383. The next prime is 3921413. The reversal of 3921405 is 5041293.

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

It is not a de Polignac number, because 3921405 - 2¹⁷ = 3790333 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130699 + ... + 130728.

It is an arithmetic number, because the mean of its divisors is an integer number (784284).

Almost surely, 2^3921405 is an apocalyptic number.

It is an amenable number.

3921405 is a deficient number, since it is larger than the sum of its proper divisors (2352867).

3921405 is a wasteful number, since it uses less digits than its factorization.

3921405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261435.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 3921405 is about 1980.2537716162. The cubic root of 3921405 is about 157.6935388485.

Adding to 3921405 its reverse (5041293), we get a palindrome (8962698).

The spelling of 3921405 in words is "three million, nine hundred twenty-one thousand, four hundred five".