1221228540000 has 720 divisors, whose sum is σ = 5041276400160. Its totient is φ = 274544640000.

The previous prime is 1221228539903. The next prime is 1221228540013. The reversal of 1221228540000 is 458221221.

1221228540000 is a `hidden beast` number, since 12 + 21 + 228 + 5 + 400 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a congruent number.

It is an unprimeable number.

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 119 ways as a sum of consecutive naturals, for example, 76852056 + ... + 76867944.

It is an arithmetic number, because the mean of its divisors is an integer number (7001772778).

Almost surely, 2^{1221228540000} is an apocalyptic number.

1221228540000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221228540000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2520638200080).

1221228540000 is an abundant number, since it is smaller than the sum of its proper divisors (3820047860160).

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

1221228540000 is a wasteful number, since it uses less digits than its factorization.

1221228540000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15993 (or 15967 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The spelling of 1221228540000 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-eight million, five hundred forty thousand".