2116021 has 2 divisors, whose sum is σ = 2116022. Its totient is φ = 2116020.

The previous prime is 2116019. The next prime is 2116027. The reversal of 2116021 is 1206112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1876900 + 239121 = 1370^2 + 489^2 .

It is a cyclic number.

It is not a de Polignac number, because 2116021 - 2¹ = 2116019 is a prime.

Together with 2116019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2115992 and 2116010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2116027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1058010 + 1058011.

It is an arithmetic number, because the mean of its divisors is an integer number (1058011).

2^2116021 is an apocalyptic number.

It is an amenable number.

2116021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2116021 is an equidigital number, since it uses as much as digits as its factorization.

2116021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2116021 is about 1454.6549419020. The cubic root of 2116021 is about 128.3827451637.

Subtracting from 2116021 its reverse (1206112), we obtain a palindrome (909909).

The spelling of 2116021 in words is "two million, one hundred sixteen thousand, twenty-one".