11781918720 has 832 divisors, whose sum is σ = 49539168000. Its totient is φ = 2618818560.

The previous prime is 11781918719. The next prime is 11781918727. The reversal of 11781918720 is 2781918711.

It is a tau number, because it is divible by the number of its divisors (832).

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 (11781918727) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 79073206 + ... + 79073354.

Almost surely, 2^11781918720 is an apocalyptic number.

11781918720 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 11781918720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24769584000).

11781918720 is an abundant number, since it is smaller than the sum of its proper divisors (37757249280).

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

11781918720 is a wasteful number, since it uses less digits than its factorization.

11781918720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 45.

Subtracting from 11781918720 its reverse (2781918711), we obtain a palindrome (9000000009).

The spelling of 11781918720 in words is "eleven billion, seven hundred eighty-one million, nine hundred eighteen thousand, seven hundred twenty".