1211504028 has 72 divisors (see below), whose sum is σ = 3293014032. Its totient is φ = 345655296.

The previous prime is 1211503999. The next prime is 1211504033. The reversal of 1211504028 is 8204051121.

It is a junction number, because it is equal to n+sod(n) for n = 1211503989 and 1211504007.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 714750 + ... + 716442.

It is an arithmetic number, because the mean of its divisors is an integer number (45736306).

Almost surely, 2^1211504028 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211504028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1646507016).

1211504028 is an abundant number, since it is smaller than the sum of its proper divisors (2081510004).

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

1211504028 is a wasteful number, since it uses less digits than its factorization.

1211504028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2931 (or 2922 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 1211504028 is about 34806.6664304412. Note that the first 3 decimals coincide. The cubic root of 1211504028 is about 1066.0435678988.

Adding to 1211504028 its reverse (8204051121), we get a palindrome (9415555149).

The spelling of 1211504028 in words is "one billion, two hundred eleven million, five hundred four thousand, twenty-eight".