99636991 has 2 divisors, whose sum is σ = 99636992. Its totient is φ = 99636990.

The previous prime is 99636941. The next prime is 99636997. The reversal of 99636991 is 19963699.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 99636991 - 2²¹ = 97539839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99636997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49818495 + 49818496.

It is an arithmetic number, because the mean of its divisors is an integer number (49818496).

Almost surely, 2^99636991 is an apocalyptic number.

99636991 is a deficient number, since it is larger than the sum of its proper divisors (1).

99636991 is an equidigital number, since it uses as much as digits as its factorization.

99636991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 708588, while the sum is 52.

The square root of 99636991 is about 9981.8330480929. The cubic root of 99636991 is about 463.5965562050.

The spelling of 99636991 in words is "ninety-nine million, six hundred thirty-six thousand, nine hundred ninety-one".