9991636493 has 2 divisors, whose sum is σ = 9991636494. Its totient is φ = 9991636492.

The previous prime is 9991636463. The next prime is 9991636507. The reversal of 9991636493 is 3946361999.

9991636493 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7871770729 + 2119865764 = 88723^2 + 46042^2 .

It is a cyclic number.

It is not a de Polignac number, because 9991636493 - 2¹² = 9991632397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9991636433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995818246 + 4995818247.

It is an arithmetic number, because the mean of its divisors is an integer number (4995818247).

Almost surely, 2^9991636493 is an apocalyptic number.

It is an amenable number.

9991636493 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991636493 is an equidigital number, since it uses as much as digits as its factorization.

9991636493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8503056, while the sum is 59.

The square root of 9991636493 is about 99958.1737178106. The cubic root of 9991636493 is about 2153.8339015237.

The spelling of 9991636493 in words is "nine billion, nine hundred ninety-one million, six hundred thirty-six thousand, four hundred ninety-three".