99997578 has 20 divisors (see below), whose sum is σ = 224069010. Its totient is φ = 33332472.

The previous prime is 99997571. The next prime is 99997609. The reversal of 99997578 is 87579999.

It can be written as a sum of positive squares in only one way, i.e., 88115769 + 11881809 = 9387^2 + 3447^2 .

It is not an unprimeable number, because it can be changed into a prime (99997571) 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 9 ways as a sum of consecutive naturals, for example, 308473 + ... + 308796.

Almost surely, 2^99997578 is an apocalyptic number.

99997578 is an abundant number, since it is smaller than the sum of its proper divisors (124071432).

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

99997578 is a wasteful number, since it uses less digits than its factorization.

99997578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617283 (or 617274 counting only the distinct ones).

The product of its digits is 12859560, while the sum is 63.

The square root of 99997578 is about 9999.8788992667. The cubic root of 99997578 is about 464.1551360216.

The spelling of 99997578 in words is "ninety-nine million, nine hundred ninety-seven thousand, five hundred seventy-eight".