99778573 has 2 divisors, whose sum is σ = 99778574. Its totient is φ = 99778572.

The previous prime is 99778571. The next prime is 99778583. The reversal of 99778573 is 37587799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99560484 + 218089 = 9978^2 + 467^2 .

It is a cyclic number.

It is not a de Polignac number, because 99778573 - 2¹ = 99778571 is a prime.

Together with 99778571, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99778571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49889286 + 49889287.

It is an arithmetic number, because the mean of its divisors is an integer number (49889287).

Almost surely, 2^99778573 is an apocalyptic number.

It is an amenable number.

99778573 is a deficient number, since it is larger than the sum of its proper divisors (1).

99778573 is an equidigital number, since it uses as much as digits as its factorization.

99778573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3333960, while the sum is 55.

The square root of 99778573 is about 9988.9225144657. The cubic root of 99778573 is about 463.8160391565.

The spelling of 99778573 in words is "ninety-nine million, seven hundred seventy-eight thousand, five hundred seventy-three".