4021421 has 4 divisors (see below), whose sum is σ = 4033692. Its totient is φ = 4009152.

The previous prime is 4021417. The next prime is 4021427. The reversal of 4021421 is 1241204.

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 2292196 + 1729225 = 1514^2 + 1315^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021421 - 2² = 4021417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 4021396 and 4021405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4021427) 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, 5630 + ... + 6303.

It is an arithmetic number, because the mean of its divisors is an integer number (1008423).

Almost surely, 2^4021421 is an apocalyptic number.

It is an amenable number.

4021421 is a deficient number, since it is larger than the sum of its proper divisors (12271).

4021421 is a wasteful number, since it uses less digits than its factorization.

4021421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12270.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 4021421 is about 2005.3480994580. The cubic root of 4021421 is about 159.0229651836.

Adding to 4021421 its reverse (1241204), we get a palindrome (5262625).

The spelling of 4021421 in words is "four million, twenty-one thousand, four hundred twenty-one".