19708121 has 2 divisors, whose sum is σ = 19708122. Its totient is φ = 19708120.

The previous prime is 19708099. The next prime is 19708127. The reversal of 19708121 is 12180791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 3748096 = 3995^2 + 1936^2 .

It is a cyclic number.

It is not a de Polignac number, because 19708121 - 2⁶ = 19708057 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19708127) 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, 9854060 + 9854061.

It is an arithmetic number, because the mean of its divisors is an integer number (9854061).

Almost surely, 2^19708121 is an apocalyptic number.

It is an amenable number.

19708121 is a deficient number, since it is larger than the sum of its proper divisors (1).

19708121 is an equidigital number, since it uses as much as digits as its factorization.

19708121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 19708121 is about 4439.3829526185. The cubic root of 19708121 is about 270.1148162800.

The spelling of 19708121 in words is "nineteen million, seven hundred eight thousand, one hundred twenty-one".