99007821 has 24 divisors (see below), whose sum is σ = 156611520. Its totient is φ = 59774400.

The previous prime is 99007817. The next prime is 99007829. The reversal of 99007821 is 12870099.

It is a happy number.

It is not a de Polignac number, because 99007821 - 2² = 99007817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99007829) 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 23 ways as a sum of consecutive naturals, for example, 26040 + ... + 29598.

It is an arithmetic number, because the mean of its divisors is an integer number (6525480).

Almost surely, 2^99007821 is an apocalyptic number.

It is an amenable number.

99007821 is a deficient number, since it is larger than the sum of its proper divisors (57603699).

99007821 is a wasteful number, since it uses less digits than its factorization.

99007821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3857 (or 3854 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 99007821 is about 9950.2673833420. The cubic root of 99007821 is about 462.6186825687.

It can be divided in two parts, 990078 and 21, that added together give a palindrome (990099).

The spelling of 99007821 in words is "ninety-nine million, seven thousand, eight hundred twenty-one".