21110320 has 160 divisors (see below), whose sum is σ = 64281600. Its totient is φ = 6251520.

The previous prime is 21110263. The next prime is 21110363. The reversal of 21110320 is 2301112.

It is a super-2 number, since 2×21110320² = 891291221004800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21110297 and 21110306.

It is a congruent number.

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, 141606 + ... + 141754.

It is an arithmetic number, because the mean of its divisors is an integer number (401760).

Almost surely, 2^21110320 is an apocalyptic number.

21110320 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 21110320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32140800).

21110320 is an abundant number, since it is smaller than the sum of its proper divisors (43171280).

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

21110320 is a wasteful number, since it uses less digits than its factorization.

21110320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21110320 is about 4594.5968267085. The cubic root of 21110320 is about 276.3746923828.

Adding to 21110320 its reverse (2301112), we get a palindrome (23411432).

The spelling of 21110320 in words is "twenty-one million, one hundred ten thousand, three hundred twenty".