21022110 has 48 divisors (see below), whose sum is σ = 55031184. Its totient is φ = 5567616.

The previous prime is 21022103. The next prime is 21022117. The reversal of 21022110 is 1122012.

It is an interprime number because it is at equal distance from previous prime (21022103) and next prime (21022117).

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 = 21022092 and 21022101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13954 + ... + 15386.

It is an arithmetic number, because the mean of its divisors is an integer number (1146483).

Almost surely, 2^21022110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21022110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27515592).

21022110 is an abundant number, since it is smaller than the sum of its proper divisors (34009074).

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

21022110 is a wasteful number, since it uses less digits than its factorization.

21022110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 21022110 is about 4584.9874590886. The cubic root of 21022110 is about 275.9892087778.

Adding to 21022110 its reverse (1122012), we get a palindrome (22144122).

The spelling of 21022110 in words is "twenty-one million, twenty-two thousand, one hundred ten".