19996993 has 2 divisors, whose sum is σ = 19996994. Its totient is φ = 19996992.

The previous prime is 19996969. The next prime is 19997011. The reversal of 19996993 is 39969991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14077504 + 5919489 = 3752^2 + 2433^2 .

It is an emirp because it is prime and its reverse (39969991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19996993 - 2⁵ = 19996961 is a prime.

It is not a weakly prime, because it can be changed into another prime (19996393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9998496 + 9998497.

It is an arithmetic number, because the mean of its divisors is an integer number (9998497).

Almost surely, 2^19996993 is an apocalyptic number.

It is an amenable number.

19996993 is a deficient number, since it is larger than the sum of its proper divisors (1).

19996993 is an equidigital number, since it uses as much as digits as its factorization.

19996993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1062882, while the sum is 55.

The square root of 19996993 is about 4471.7997495416. The cubic root of 19996993 is about 271.4281572214.

The spelling of 19996993 in words is "nineteen million, nine hundred ninety-six thousand, nine hundred ninety-three".