1228891980 has 24 divisors (see below), whose sum is σ = 3440897712. Its totient is φ = 327704512.

The previous prime is 1228891949. The next prime is 1228891981. The reversal of 1228891980 is 891988221.

It is not an unprimeable number, because it can be changed into a prime (1228891981) 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 7 ways as a sum of consecutive naturals, for example, 10240707 + ... + 10240826.

It is an arithmetic number, because the mean of its divisors is an integer number (143370738).

Almost surely, 2^1228891980 is an apocalyptic number.

1228891980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1228891980 is an abundant number, since it is smaller than the sum of its proper divisors (2212005732).

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

1228891980 is a wasteful number, since it uses less digits than its factorization.

1228891980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20481545 (or 20481543 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 48.

The square root of 1228891980 is about 35055.5556224687. Note that the first 3 decimals coincide. The cubic root of 1228891980 is about 1071.1194444832.

The spelling of 1228891980 in words is "one billion, two hundred twenty-eight million, eight hundred ninety-one thousand, nine hundred eighty".