11201221020 has 96 divisors (see below), whose sum is σ = 34444569600. Its totient is φ = 2697199360.

The previous prime is 11201221013. The next prime is 11201221027. The reversal of 11201221020 is 2012210211.

It is an interprime number because it is at equal distance from previous prime (11201221013) and next prime (11201221027).

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 = 11201220987 and 11201221005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11201221027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 41389 + ... + 155291.

It is an arithmetic number, because the mean of its divisors is an integer number (358797600).

Almost surely, 2^11201221020 is an apocalyptic number.

11201221020 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 11201221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17222284800).

11201221020 is an abundant number, since it is smaller than the sum of its proper divisors (23243348580).

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

11201221020 is a wasteful number, since it uses less digits than its factorization.

11201221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114075 (or 114073 counting only the distinct ones).

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

Adding to 11201221020 its reverse (2012210211), we get a palindrome (13213431231).

It can be divided in two parts, 11201 and 221020, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 11201221020 in words is "eleven billion, two hundred one million, two hundred twenty-one thousand, twenty".