11155509720 has 96 divisors (see below), whose sum is σ = 36295197120. Its totient is φ = 2971537920.

The previous prime is 11155509719. The next prime is 11155509733. The reversal of 11155509720 is 2790555111.

11155509720 is a `hidden beast` number, since 1 + 1 + 15 + 550 + 97 + 2 + 0 = 666.

11155509720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×11155509720² (a number of 21 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 320785 + ... + 353855.

It is an arithmetic number, because the mean of its divisors is an integer number (378074970).

Almost surely, 2^11155509720 is an apocalyptic number.

11155509720 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 11155509720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18147598560).

11155509720 is an abundant number, since it is smaller than the sum of its proper divisors (25139687400).

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

11155509720 is a wasteful number, since it uses less digits than its factorization.

11155509720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34025 (or 34018 counting only the distinct ones).

The product of its (nonzero) digits is 15750, while the sum is 36.

The spelling of 11155509720 in words is "eleven billion, one hundred fifty-five million, five hundred nine thousand, seven hundred twenty".