19933997 has 2 divisors, whose sum is σ = 19933998. Its totient is φ = 19933996.

The previous prime is 19933987. The next prime is 19933999. The reversal of 19933997 is 79933991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14523721 + 5410276 = 3811^2 + 2326^2 .

It is an emirp because it is prime and its reverse (79933991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19933997 - 2¹² = 19929901 is a prime.

Together with 19933999, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19933999) 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, 9966998 + 9966999.

It is an arithmetic number, because the mean of its divisors is an integer number (9966999).

Almost surely, 2^19933997 is an apocalyptic number.

It is an amenable number.

19933997 is a deficient number, since it is larger than the sum of its proper divisors (1).

19933997 is an equidigital number, since it uses as much as digits as its factorization.

19933997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 413343, while the sum is 50.

The square root of 19933997 is about 4464.7504969483. The cubic root of 19933997 is about 271.1428330716.

The spelling of 19933997 in words is "nineteen million, nine hundred thirty-three thousand, nine hundred ninety-seven".