99887778 has 24 divisors (see below), whose sum is σ = 217681308. Its totient is φ = 33102432.

The previous prime is 99887771. The next prime is 99887779. The reversal of 99887778 is 87778899.

It can be written as a sum of positive squares in 2 ways, for example, as 68112009 + 31775769 = 8253^2 + 5637^2 .

It is not an unprimeable number, because it can be changed into a prime (99887771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12925 + ... + 19152.

Almost surely, 2^99887778 is an apocalyptic number.

99887778 is an abundant number, since it is smaller than the sum of its proper divisors (117793530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99887778 is a wasteful number, since it uses less digits than its factorization.

99887778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32258 (or 32255 counting only the distinct ones).

The product of its digits is 14224896, while the sum is 63.

The square root of 99887778 is about 9994.3873248939. The cubic root of 99887778 is about 463.9851889099.

It can be divided in two parts, 9988 and 7778, that added together give a triangular number (17766 = T₁₈₈).

The spelling of 99887778 in words is "ninety-nine million, eight hundred eighty-seven thousand, seven hundred seventy-eight".