2118021 has 8 divisors (see below), whose sum is σ = 2837280. Its totient is φ = 1405392.

The previous prime is 2118007. The next prime is 2118023. The reversal of 2118021 is 1208112.

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

It is not a de Polignac number, because 2118021 - 2⁷ = 2117893 is a prime.

2118021 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 855 + ... + 2228.

It is an arithmetic number, because the mean of its divisors is an integer number (354660).

2^2118021 is an apocalyptic number.

It is an amenable number.

2118021 is a deficient number, since it is larger than the sum of its proper divisors (719259).

2118021 is a wasteful number, since it uses less digits than its factorization.

2118021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3315.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 2118021 is about 1455.3422277939. The cubic root of 2118021 is about 128.4231802755.

Subtracting from 2118021 its reverse (1208112), we obtain a palindrome (909909).

The spelling of 2118021 in words is "two million, one hundred eighteen thousand, twenty-one".