11011221000 has 320 divisors, whose sum is σ = 41455093680. Its totient is φ = 2710195200.

The previous prime is 11011220999. The next prime is 11011221007. The reversal of 11011221000 is 12211011.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 525051396 + 10486169604 = 22914^2 + 102402^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (11011221007) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1047772 + ... + 1058228.

Almost surely, 2^11011221000 is an apocalyptic number.

11011221000 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 11011221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20727546840).

11011221000 is an abundant number, since it is smaller than the sum of its proper divisors (30443872680).

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

11011221000 is a wasteful number, since it uses less digits than its factorization.

11011221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10503 (or 10480 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 11011221000 its reverse (12211011), we get a palindrome (11023432011).

The spelling of 11011221000 in words is "eleven billion, eleven million, two hundred twenty-one thousand".