1221728781260 has 24 divisors (see below), whose sum is σ = 2762986628976. Its totient is φ = 451099857600.

The previous prime is 1221728781241. The next prime is 1221728781289. The reversal of 1221728781260 is 621878271221.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2349478166 + ... + 2349478685.

It is an arithmetic number, because the mean of its divisors is an integer number (115124442874).

Almost surely, 2^{1221728781260} is an apocalyptic number.

1221728781260 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221728781260 is an abundant number, since it is smaller than the sum of its proper divisors (1541257847716).

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

1221728781260 is a wasteful number, since it uses less digits than its factorization.

1221728781260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4698956873 (or 4698956871 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 47.

The spelling of 1221728781260 in words is "one trillion, two hundred twenty-one billion, seven hundred twenty-eight million, seven hundred eighty-one thousand, two hundred sixty".