99997078 has 4 divisors (see below), whose sum is σ = 149995620. Its totient is φ = 49998538.

The previous prime is 99997069. The next prime is 99997081. The reversal of 99997078 is 87079999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87079999 = 8429 ⋅10331.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 24999268 + ... + 24999271.

It is an arithmetic number, because the mean of its divisors is an integer number (37498905).

Almost surely, 2^99997078 is an apocalyptic number.

99997078 is a deficient number, since it is larger than the sum of its proper divisors (49998542).

99997078 is a wasteful number, since it uses less digits than its factorization.

99997078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49998541.

The product of its (nonzero) digits is 2571912, while the sum is 58.

The square root of 99997078 is about 9999.8538989327. The cubic root of 99997078 is about 464.1543624097.

The spelling of 99997078 in words is "ninety-nine million, nine hundred ninety-seven thousand, seventy-eight".