1221864652800 has 1632 divisors, whose sum is σ = 5117682923520. Its totient is φ = 286654464000.

The previous prime is 1221864652787. The next prime is 1221864652807. The reversal of 1221864652800 is 82564681221.

1221864652800 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 86 + 46 + 528 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221864652807) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 39414988785 + ... + 39414988815.

Almost surely, 2^{1221864652800} is an apocalyptic number.

1221864652800 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 1221864652800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2558841461760).

1221864652800 is an abundant number, since it is smaller than the sum of its proper divisors (3895818270720).

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

1221864652800 is an frugal number, since it uses more digits than its factorization.

1221864652800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 1221864652800 in words is "one trillion, two hundred twenty-one billion, eight hundred sixty-four million, six hundred fifty-two thousand, eight hundred".