11555617920 has 256 divisors, whose sum is σ = 45922913280. Its totient is φ = 2401136640.

The previous prime is 11555617883. The next prime is 11555617937. The reversal of 11555617920 is 2971655511.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108759 + ... + 186921.

It is an arithmetic number, because the mean of its divisors is an integer number (179386380).

Almost surely, 2^11555617920 is an apocalyptic number.

11555617920 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 11555617920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22961456640).

11555617920 is an abundant number, since it is smaller than the sum of its proper divisors (34367295360).

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

11555617920 is a wasteful number, since it uses less digits than its factorization.

11555617920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78203 (or 78191 counting only the distinct ones).

The product of its (nonzero) digits is 94500, while the sum is 42.

The spelling of 11555617920 in words is "eleven billion, five hundred fifty-five million, six hundred seventeen thousand, nine hundred twenty".