99921847 has 2 divisors, whose sum is σ = 99921848. Its totient is φ = 99921846.

The previous prime is 99921839. The next prime is 99921881. The reversal of 99921847 is 74812999.

It is a weak prime.

It is an emirp because it is prime and its reverse (74812999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99921847 - 2³ = 99921839 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 99921847.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99921047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49960923 + 49960924.

It is an arithmetic number, because the mean of its divisors is an integer number (49960924).

Almost surely, 2^99921847 is an apocalyptic number.

99921847 is a deficient number, since it is larger than the sum of its proper divisors (1).

99921847 is an equidigital number, since it uses as much as digits as its factorization.

99921847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 49.

The square root of 99921847 is about 9996.0915862151. The cubic root of 99921847 is about 464.0379338165.

The spelling of 99921847 in words is "ninety-nine million, nine hundred twenty-one thousand, eight hundred forty-seven".