2149421 has 2 divisors, whose sum is σ = 2149422. Its totient is φ = 2149420.

The previous prime is 2149409. The next prime is 2149453. The reversal of 2149421 is 1249412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1177225 + 972196 = 1085^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 2149421 - 2¹⁰ = 2148397 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2149471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1074710 + 1074711.

It is an arithmetic number, because the mean of its divisors is an integer number (1074711).

2^2149421 is an apocalyptic number.

It is an amenable number.

2149421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2149421 is an equidigital number, since it uses as much as digits as its factorization.

2149421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 23.

The square root of 2149421 is about 1466.0903792059. The cubic root of 2149421 is about 129.0547010767.

Subtracting from 2149421 its reverse (1249412), we obtain a palindrome (900009).

The spelling of 2149421 in words is "two million, one hundred forty-nine thousand, four hundred twenty-one".