989928821 has 12 divisors (see below), whose sum is σ = 1182674988. Its totient is φ = 825576192.

The previous prime is 989928817. The next prime is 989928839. The reversal of 989928821 is 128829989.

989928821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 337126321 + 652802500 = 18361^2 + 25550^2 .

It is not a de Polignac number, because 989928821 - 2² = 989928817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989928851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 271196 + ... + 274821.

It is an arithmetic number, because the mean of its divisors is an integer number (98556249).

Almost surely, 2^989928821 is an apocalyptic number.

It is an amenable number.

989928821 is a deficient number, since it is larger than the sum of its proper divisors (192746167).

989928821 is a wasteful number, since it uses less digits than its factorization.

989928821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546068 (or 546061 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 56.

The square root of 989928821 is about 31463.1343162120. The cubic root of 989928821 is about 996.6316070013.

The spelling of 989928821 in words is "nine hundred eighty-nine million, nine hundred twenty-eight thousand, eight hundred twenty-one".