99857869 has 2 divisors, whose sum is σ = 99857870.
Its totient is φ = 99857868.
The previous prime is 99857867. The next prime is 99857873. The reversal of 99857869 is 96875899.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 88548100 + 11309769 = 9410^2 + 3363^2
It is a cyclic number.
It is not a de Polignac number, because 99857869 - 21 = 99857867 is a prime.
It is a super-2 number, since 2×998578692 = 19943188002442322, which contains 22 as substring.
Together with 99857867, it forms a pair of twin primes.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (99857861) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49928934 + 49928935.
It is an arithmetic number, because the mean of its divisors is an integer number (49928935).
Almost surely, 299857869 is an apocalyptic number.
It is an amenable number.
99857869 is a deficient number, since it is larger than the sum of its proper divisors (1).
99857869 is an equidigital number, since it uses as much as digits as its factorization.
99857869 is an evil number, because the sum of its binary digits is even.
The product of its digits is 9797760, while the sum is 61.
The square root of 99857869 is about 9992.8909230512.
The cubic root of 99857869 is about 463.9388745406.
The spelling of 99857869 in words is "ninety-nine million, eight hundred fifty-seven thousand, eight hundred sixty-nine".