111100021020 has 288 divisors, whose sum is σ = 348897669120. Its totient is φ = 28603860480.

The previous prime is 111100021007. The next prime is 111100021033. The reversal of 111100021020 is 20120001111.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (111100021007) and next prime (111100021033).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 111100020993 and 111100021011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 228131217 + ... + 228131703.

It is an arithmetic number, because the mean of its divisors is an integer number (1211450240).

Almost surely, 2^111100021020 is an apocalyptic number.

111100021020 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 111100021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174448834560).

111100021020 is an abundant number, since it is smaller than the sum of its proper divisors (237797648100).

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

111100021020 is a wasteful number, since it uses less digits than its factorization.

111100021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905 (or 900 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 111100021020 its reverse (20120001111), we get a palindrome (131220022131).

The spelling of 111100021020 in words is "one hundred eleven billion, one hundred million, twenty-one thousand, twenty".