11211221020 has 48 divisors (see below), whose sum is σ = 23710615488. Its totient is φ = 4452730880.

The previous prime is 11211220973. The next prime is 11211221023. The reversal of 11211221020 is 2012211211.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211221023) 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, 5386380 + ... + 5388460.

It is an arithmetic number, because the mean of its divisors is an integer number (493971156).

Almost surely, 2^11211221020 is an apocalyptic number.

11211221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11211221020 is an abundant number, since it is smaller than the sum of its proper divisors (12499394468).

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

11211221020 is a wasteful number, since it uses less digits than its factorization.

11211221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3870 (or 3868 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 11211221020 its reverse (2012211211), we get a palindrome (13223432231).

The spelling of 11211221020 in words is "eleven billion, two hundred eleven million, two hundred twenty-one thousand, twenty".