3840421 has 4 divisors (see below), whose sum is σ = 4135852. Its totient is φ = 3544992.

The previous prime is 3840409. The next prime is 3840449. The reversal of 3840421 is 1240483.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1852321 + 1988100 = 1361^2 + 1410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3840421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3840392 and 3840401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3840401) 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, 147696 + ... + 147721.

It is an arithmetic number, because the mean of its divisors is an integer number (1033963).

Almost surely, 2^3840421 is an apocalyptic number.

It is an amenable number.

3840421 is a deficient number, since it is larger than the sum of its proper divisors (295431).

3840421 is a wasteful number, since it uses less digits than its factorization.

3840421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295430.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 3840421 is about 1959.6992116139. The cubic root of 3840421 is about 156.6004282129.

The spelling of 3840421 in words is "three million, eight hundred forty thousand, four hundred twenty-one".