2106421 has 2 divisors, whose sum is σ = 2106422. Its totient is φ = 2106420.

The previous prime is 2106407. The next prime is 2106427. The reversal of 2106421 is 1246012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1134225 + 972196 = 1065^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 2106421 - 2⁵ = 2106389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2106395 and 2106404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2106427) 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 as a sum of consecutive naturals, namely, 1053210 + 1053211.

It is an arithmetic number, because the mean of its divisors is an integer number (1053211).

2^2106421 is an apocalyptic number.

It is an amenable number.

2106421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2106421 is an equidigital number, since it uses as much as digits as its factorization.

2106421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2106421 is about 1451.3514391766. The cubic root of 2106421 is about 128.1883011416.

The spelling of 2106421 in words is "two million, one hundred six thousand, four hundred twenty-one".