19993087 has 2 divisors, whose sum is σ = 19993088. Its totient is φ = 19993086.

The previous prime is 19993013. The next prime is 19993097. The reversal of 19993087 is 78039991.

It is a strong prime.

It is an emirp because it is prime and its reverse (78039991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19993087 - 2¹¹ = 19991039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19993007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9996543 + 9996544.

It is an arithmetic number, because the mean of its divisors is an integer number (9996544).

Almost surely, 2^19993087 is an apocalyptic number.

19993087 is a deficient number, since it is larger than the sum of its proper divisors (1).

19993087 is an equidigital number, since it uses as much as digits as its factorization.

19993087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 19993087 is about 4471.3629913037. The cubic root of 19993087 is about 271.4104834405.

The spelling of 19993087 in words is "nineteen million, nine hundred ninety-three thousand, eighty-seven".