11001221220 has 192 divisors, whose sum is σ = 35899428096. Its totient is φ = 2487582720.

The previous prime is 11001221207. The next prime is 11001221233. The reversal of 11001221220 is 2212210011.

It is an interprime number because it is at equal distance from previous prime (11001221207) and next prime (11001221233).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 11001221196 and 11001221205.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1263522 + ... + 1272198.

It is an arithmetic number, because the mean of its divisors is an integer number (186976188).

Almost surely, 2^11001221220 is an apocalyptic number.

11001221220 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 11001221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17949714048).

11001221220 is an abundant number, since it is smaller than the sum of its proper divisors (24898206876).

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

11001221220 is a wasteful number, since it uses less digits than its factorization.

11001221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8830 (or 8828 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 11001221220 its reverse (2212210011), we get a palindrome (13213431231).

It can be divided in two parts, 11001 and 221220, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 11001221220 in words is "eleven billion, one million, two hundred twenty-one thousand, two hundred twenty".