1221770188800 has 864 divisors, whose sum is σ = 5107698086400. Its totient is φ = 273286103040.

The previous prime is 1221770188741. The next prime is 1221770188813. The reversal of 1221770188800 is 88810771221.

It is a happy number.

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

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 71 ways as a sum of consecutive naturals, for example, 151599171 + ... + 151607229.

It is an arithmetic number, because the mean of its divisors is an integer number (5911687600).

Almost surely, 2^{1221770188800} is an apocalyptic number.

1221770188800 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 1221770188800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2553849043200).

1221770188800 is an abundant number, since it is smaller than the sum of its proper divisors (3885927897600).

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

1221770188800 is a wasteful number, since it uses less digits than its factorization.

1221770188800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8151 (or 8123 counting only the distinct ones).

The product of its (nonzero) digits is 100352, while the sum is 45.

The spelling of 1221770188800 in words is "one trillion, two hundred twenty-one billion, seven hundred seventy million, one hundred eighty-eight thousand, eight hundred".