99821866 has 8 divisors (see below), whose sum is σ = 151415460. Its totient is φ = 49350048.

The previous prime is 99821861. The next prime is 99821927. The reversal of 99821866 is 66812899.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 87815641 + 12006225 = 9371^2 + 3465^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (99821861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 280221 + ... + 280576.

Almost surely, 2^99821866 is an apocalyptic number.

99821866 is a deficient number, since it is larger than the sum of its proper divisors (51593594).

99821866 is a wasteful number, since it uses less digits than its factorization.

99821866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560888.

The product of its digits is 373248, while the sum is 49.

The square root of 99821866 is about 9991.0893299980. The cubic root of 99821866 is about 463.8831112867.

The spelling of 99821866 in words is "ninety-nine million, eight hundred twenty-one thousand, eight hundred sixty-six".