1221769785600 has 2592 divisors, whose sum is σ = 5696007932160. Its totient is φ = 252255928320.

The previous prime is 1221769785563. The next prime is 1221769785601. The reversal of 1221769785600 is 65879671221.

1221769785600 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 7 + 6 + 9 + 78 + 560 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2592).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1221769785601) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 12595564752 + ... + 12595564848.

Almost surely, 2^{1221769785600} is an apocalyptic number.

1221769785600 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 1221769785600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2848003966080).

1221769785600 is an abundant number, since it is smaller than the sum of its proper divisors (4474238146560).

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

1221769785600 is an equidigital number, since it uses as much as digits as its factorization.

1221769785600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The spelling of 1221769785600 in words is "one trillion, two hundred twenty-one billion, seven hundred sixty-nine million, seven hundred eighty-five thousand, six hundred".