99997878 has 32 divisors (see below), whose sum is σ = 208530432. Its totient is φ = 31932000.

The previous prime is 99997873. The next prime is 99997879. The reversal of 99997878 is 87879999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99997871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16125 + ... + 21447.

It is an arithmetic number, because the mean of its divisors is an integer number (6516576).

Almost surely, 2^99997878 is an apocalyptic number.

99997878 is an abundant number, since it is smaller than the sum of its proper divisors (108532554).

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

99997878 is a wasteful number, since it uses less digits than its factorization.

99997878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5460.

The product of its digits is 20575296, while the sum is 66.

The square root of 99997878 is about 9999.8938994371. The cubic root of 99997878 is about 464.1556001876.

The spelling of 99997878 in words is "ninety-nine million, nine hundred ninety-seven thousand, eight hundred seventy-eight".