2140021 has 4 divisors (see below), whose sum is σ = 2304652. Its totient is φ = 1975392.

The previous prime is 2140013. The next prime is 2140049. The reversal of 2140021 is 1200412.

2140021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 792100 + 1347921 = 890^2 + 1161^2 .

It is a cyclic number.

It is not a de Polignac number, because 2140021 - 2³ = 2140013 is a prime.

It is a Duffinian number.

2140021 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2140001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82296 + ... + 82321.

It is an arithmetic number, because the mean of its divisors is an integer number (576163).

2^2140021 is an apocalyptic number.

It is an amenable number.

2140021 is a deficient number, since it is larger than the sum of its proper divisors (164631).

2140021 is a wasteful number, since it uses less digits than its factorization.

2140021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164630.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 2140021 is about 1462.8810614674. The cubic root of 2140021 is about 128.8662957767.

Adding to 2140021 its reverse (1200412), we get a palindrome (3340433).

The spelling of 2140021 in words is "two million, one hundred forty thousand, twenty-one".