11581211000 has 64 divisors (see below), whose sum is σ = 27118709280. Its totient is φ = 4629292800.

The previous prime is 11581210973. The next prime is 11581211003. The reversal of 11581211000 is 11218511.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11581211003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1903964 + ... + 1910036.

Almost surely, 2^11581211000 is an apocalyptic number.

11581211000 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 11581211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13559354640).

11581211000 is an abundant number, since it is smaller than the sum of its proper divisors (15537498280).

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

11581211000 is a wasteful number, since it uses less digits than its factorization.

11581211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8001 (or 7987 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 20.

Adding to 11581211000 its reverse (11218511), we get a palindrome (11592429511).

The spelling of 11581211000 in words is "eleven billion, five hundred eighty-one million, two hundred eleven thousand".