2197421 has 2 divisors, whose sum is σ = 2197422. Its totient is φ = 2197420.

The previous prime is 2197411. The next prime is 2197427. The reversal of 2197421 is 1247912.

2197421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1999396 + 198025 = 1414^2 + 445^2 .

It is a cyclic number.

It is not a de Polignac number, because 2197421 - 2⁶ = 2197357 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2197427) 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 as a sum of consecutive naturals, namely, 1098710 + 1098711.

It is an arithmetic number, because the mean of its divisors is an integer number (1098711).

2^2197421 is an apocalyptic number.

It is an amenable number.

2197421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2197421 is an equidigital number, since it uses as much as digits as its factorization.

2197421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 26.

The square root of 2197421 is about 1482.3700617592. The cubic root of 2197421 is about 130.0083032172.

The spelling of 2197421 in words is "two million, one hundred ninety-seven thousand, four hundred twenty-one".