20111121380 has 96 divisors (see below), whose sum is σ = 51296136192. Its totient is φ = 6465484800.

The previous prime is 20111121379. The next prime is 20111121421. The reversal of 20111121380 is 8312111102.

It is a happy number.

It is a super-2 number, since 2×20111121380² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 629390 + ... + 660570.

It is an arithmetic number, because the mean of its divisors is an integer number (534334752).

Almost surely, 2^20111121380 is an apocalyptic number.

20111121380 is a gapful number since it is divisible by the number (20) 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 20111121380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25648068096).

20111121380 is an abundant number, since it is smaller than the sum of its proper divisors (31185014812).

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

20111121380 is a wasteful number, since it uses less digits than its factorization.

20111121380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31485 (or 31483 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 20111121380 its reverse (8312111102), we get a palindrome (28423232482).

The spelling of 20111121380 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, three hundred eighty".