1228920828 has 12 divisors (see below), whose sum is σ = 2867481960. Its totient is φ = 409640272.

The previous prime is 1228920821. The next prime is 1228920829. The reversal of 1228920828 is 8280298221.

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 1228920828.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1228920821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51205023 + ... + 51205046.

It is an arithmetic number, because the mean of its divisors is an integer number (238956830).

Almost surely, 2^1228920828 is an apocalyptic number.

It is an amenable number.

1228920828 is an abundant number, since it is smaller than the sum of its proper divisors (1638561132).

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

1228920828 is a wasteful number, since it uses less digits than its factorization.

1228920828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102410076 (or 102410074 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 42.

The square root of 1228920828 is about 35055.9670812260. The cubic root of 1228920828 is about 1071.1278258578.

The spelling of 1228920828 in words is "one billion, two hundred twenty-eight million, nine hundred twenty thousand, eight hundred twenty-eight".