19684993 has 2 divisors, whose sum is σ = 19684994. Its totient is φ = 19684992.

The previous prime is 19684991. The next prime is 19685009. The reversal of 19684993 is 39948691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13593969 + 6091024 = 3687^2 + 2468^2 .

It is a cyclic number.

It is not a de Polignac number, because 19684993 - 2¹ = 19684991 is a prime.

Together with 19684991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19684991) 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, 9842496 + 9842497.

It is an arithmetic number, because the mean of its divisors is an integer number (9842497).

Almost surely, 2^19684993 is an apocalyptic number.

It is an amenable number.

19684993 is a deficient number, since it is larger than the sum of its proper divisors (1).

19684993 is an equidigital number, since it uses as much as digits as its factorization.

19684993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 49.

The square root of 19684993 is about 4436.7773214350. Note that the first 3 decimals coincide. The cubic root of 19684993 is about 270.0091126325.

The spelling of 19684993 in words is "nineteen million, six hundred eighty-four thousand, nine hundred ninety-three".