4140021 has 4 divisors (see below), whose sum is σ = 5520032. Its totient is φ = 2760012.

The previous prime is 4140001. The next prime is 4140029. The reversal of 4140021 is 1200414.

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 not a de Polignac number, because 4140021 - 2¹⁰ = 4138997 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 4139979 and 4140006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4140029) 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, 690001 + ... + 690006.

It is an arithmetic number, because the mean of its divisors is an integer number (1380008).

Almost surely, 2^4140021 is an apocalyptic number.

It is an amenable number.

4140021 is a deficient number, since it is larger than the sum of its proper divisors (1380011).

4140021 is a wasteful number, since it uses less digits than its factorization.

4140021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1380010.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 4140021 is about 2034.7041553995. The cubic root of 4140021 is about 160.5711488593.

Adding to 4140021 its reverse (1200414), we get a palindrome (5340435).

The spelling of 4140021 in words is "four million, one hundred forty thousand, twenty-one".