99870811 has 4 divisors (see below), whose sum is σ = 102193432. Its totient is φ = 97548192.

The previous prime is 99870787. The next prime is 99870833. The reversal of 99870811 is 11807899.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 99870811 - 2⁵ = 99870779 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 2322577 = 99870811 / (9 + 9 + 8 + 7 + 0 + 8 + 1 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99870011) 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 3 ways as a sum of consecutive naturals, for example, 1161246 + ... + 1161331.

It is an arithmetic number, because the mean of its divisors is an integer number (25548358).

Almost surely, 2^99870811 is an apocalyptic number.

99870811 is a deficient number, since it is larger than the sum of its proper divisors (2322621).

99870811 is a wasteful number, since it uses less digits than its factorization.

99870811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2322620.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 99870811 is about 9993.5384624266. The cubic root of 99870811 is about 463.9589164849.

The spelling of 99870811 in words is "ninety-nine million, eight hundred seventy thousand, eight hundred eleven".