20349421 has 2 divisors, whose sum is σ = 20349422. Its totient is φ = 20349420.

The previous prime is 20349389. The next prime is 20349431. The reversal of 20349421 is 12494302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19900521 + 448900 = 4461^2 + 670^2 .

It is a cyclic number.

It is not a de Polignac number, because 20349421 - 2⁵ = 20349389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20349431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10174710 + 10174711.

It is an arithmetic number, because the mean of its divisors is an integer number (10174711).

Almost surely, 2^20349421 is an apocalyptic number.

It is an amenable number.

20349421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20349421 is an equidigital number, since it uses as much as digits as its factorization.

20349421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20349421 is about 4511.0332519280. The cubic root of 20349421 is about 273.0134348248.

The spelling of 20349421 in words is "twenty million, three hundred forty-nine thousand, four hundred twenty-one".