1221098028 has 12 divisors (see below), whose sum is σ = 2849228760. Its totient is φ = 407032672.

The previous prime is 1221098027. The next prime is 1221098033. The reversal of 1221098028 is 8208901221.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 1221098028.

It is not an unprimeable number, because it can be changed into a prime (1221098027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50879073 + ... + 50879096.

It is an arithmetic number, because the mean of its divisors is an integer number (237435730).

Almost surely, 2^1221098028 is an apocalyptic number.

It is an amenable number.

1221098028 is an abundant number, since it is smaller than the sum of its proper divisors (1628130732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221098028 is a wasteful number, since it uses less digits than its factorization.

1221098028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101758176 (or 101758174 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 1221098028 is about 34944.2130831415. The cubic root of 1221098028 is about 1068.8502011179.

Adding to 1221098028 its reverse (8208901221), we get a palindrome (9429999249).

The spelling of 1221098028 in words is "one billion, two hundred twenty-one million, ninety-eight thousand, twenty-eight".