990822121 has 4 divisors (see below), whose sum is σ = 1009516932. Its totient is φ = 972127312.

The previous prime is 990822109. The next prime is 990822139. The reversal of 990822121 is 121228099.

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

It can be written as a sum of positive squares in 2 ways, for example, as 896343721 + 94478400 = 29939^2 + 9720^2 .

It is a cyclic number.

It is not a de Polignac number, because 990822121 - 2¹⁵ = 990789353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990822191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9347326 + ... + 9347431.

It is an arithmetic number, because the mean of its divisors is an integer number (252379233).

Almost surely, 2^990822121 is an apocalyptic number.

It is an amenable number.

990822121 is a deficient number, since it is larger than the sum of its proper divisors (18694811).

990822121 is a wasteful number, since it uses less digits than its factorization.

990822121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18694810.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 990822121 is about 31477.3270942753. The cubic root of 990822121 is about 996.9312997111.

The spelling of 990822121 in words is "nine hundred ninety million, eight hundred twenty-two thousand, one hundred twenty-one".