99999155 has 4 divisors (see below), whose sum is σ = 119998992. Its totient is φ = 79999320.

The previous prime is 99999131. The next prime is 99999157. The reversal of 99999155 is 55199999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55199999 = 283 ⋅195053.

It is not a de Polignac number, because 99999155 - 2¹² = 99995059 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 99999155.

It is not an unprimeable number, because it can be changed into a prime (99999157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9999911 + ... + 9999920.

It is an arithmetic number, because the mean of its divisors is an integer number (29999748).

Almost surely, 2^99999155 is an apocalyptic number.

99999155 is a deficient number, since it is larger than the sum of its proper divisors (19999837).

99999155 is a wasteful number, since it uses less digits than its factorization.

99999155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19999836.

The product of its digits is 1476225, while the sum is 56.

The square root of 99999155 is about 9999.9577499107. The cubic root of 99999155 is about 464.1575759767.

The spelling of 99999155 in words is "ninety-nine million, nine hundred ninety-nine thousand, one hundred fifty-five".