21101120 has 112 divisors (see below), whose sum is σ = 54425088. Its totient is φ = 7772160.

The previous prime is 21101033. The next prime is 21101123. The reversal of 21101120 is 2110112.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a junction number, because it is equal to n+sod(n) for n = 21101098 and 21101107.

It is not an unprimeable number, because it can be changed into a prime (21101123) 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, 345890 + ... + 345950.

Almost surely, 2^21101120 is an apocalyptic number.

21101120 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 21101120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27212544).

21101120 is an abundant number, since it is smaller than the sum of its proper divisors (33323968).

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

21101120 is a wasteful number, since it uses less digits than its factorization.

21101120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 21101120 is about 4593.5955416210. The cubic root of 21101120 is about 276.3345379839.

Adding to 21101120 its reverse (2110112), we get a palindrome (23211232).

The spelling of 21101120 in words is "twenty-one million, one hundred one thousand, one hundred twenty".