11981515680 has 192 divisors, whose sum is σ = 44402359680. Its totient is φ = 3007107072.

The previous prime is 11981515673. The next prime is 11981515681. The reversal of 11981515680 is 8651518911.

11981515680 is a `hidden beast` number, since 1 + 1 + 9 + 81 + 5 + 1 + 568 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (11981515681) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8134 + ... + 155013.

It is an arithmetic number, because the mean of its divisors is an integer number (231262290).

Almost surely, 2^11981515680 is an apocalyptic number.

11981515680 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 11981515680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22201179840).

11981515680 is an abundant number, since it is smaller than the sum of its proper divisors (32420844000).

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

11981515680 is a wasteful number, since it uses less digits than its factorization.

11981515680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163188 (or 163174 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 45.

The spelling of 11981515680 in words is "eleven billion, nine hundred eighty-one million, five hundred fifteen thousand, six hundred eighty".