20121211220 has 48 divisors (see below), whose sum is σ = 48807396288. Its totient is φ = 6886402560.

The previous prime is 20121211171. The next prime is 20121211267. The reversal of 20121211220 is 2211212102.

It is a super-3 number, since 3×20121211220³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20121211195 and 20121211204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2686262 + ... + 2693741.

It is an arithmetic number, because the mean of its divisors is an integer number (1016820756).

Almost surely, 2^20121211220 is an apocalyptic number.

20121211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121211220 is an abundant number, since it is smaller than the sum of its proper divisors (28686185068).

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

20121211220 is a wasteful number, since it uses less digits than its factorization.

20121211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5380040 (or 5380038 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121211220 its reverse (2211212102), we get a palindrome (22332423322).

The spelling of 20121211220 in words is "twenty billion, one hundred twenty-one million, two hundred eleven thousand, two hundred twenty".