1191721144320 has 1404 divisors, whose sum is σ = 5017341383964. Its totient is φ = 270888468480.

The previous prime is 1191721144319. The next prime is 1191721144337. The reversal of 1191721144320 is 234411271911.

1191721144320 is a `hidden beast` number, since 1 + 1 + 9 + 1 + 7 + 211 + 4 + 432 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 159335092224 + 1032386052096 = 399168^2 + 1016064^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 6584094630 + ... + 6584094810.

Almost surely, 2^{1191721144320} is an apocalyptic number.

1191721144320 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 1191721144320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2508670691982).

1191721144320 is an abundant number, since it is smaller than the sum of its proper divisors (3825620239644).

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

1191721144320 is an frugal number, since it uses more digits than its factorization.

1191721144320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The spelling of 1191721144320 in words is "one trillion, one hundred ninety-one billion, seven hundred twenty-one million, one hundred forty-four thousand, three hundred twenty".