99865555 has 4 divisors (see below), whose sum is σ = 119838672. Its totient is φ = 79892440.

The previous prime is 99865541. The next prime is 99865567. The reversal of 99865555 is 55556899.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55556899 = 1019 ⋅54521.

It is not a de Polignac number, because 99865555 - 2⁷ = 99865427 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9986551 + ... + 9986560.

It is an arithmetic number, because the mean of its divisors is an integer number (29959668).

Almost surely, 2^99865555 is an apocalyptic number.

99865555 is a deficient number, since it is larger than the sum of its proper divisors (19973117).

99865555 is a wasteful number, since it uses less digits than its factorization.

99865555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19973116.

The product of its digits is 2430000, while the sum is 52.

The square root of 99865555 is about 9993.2754890476. The cubic root of 99865555 is about 463.9507772671.

The spelling of 99865555 in words is "ninety-nine million, eight hundred sixty-five thousand, five hundred fifty-five".