21451122 has 144 divisors (see below), whose sum is σ = 61860960. Its totient is φ = 5488560.

The previous prime is 21451121. The next prime is 21451139. The reversal of 21451122 is 22115412.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21451095 and 21451104.

It is not an unprimeable number, because it can be changed into a prime (21451121) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 320133 + ... + 320199.

It is an arithmetic number, because the mean of its divisors is an integer number (429590).

Almost surely, 2^21451122 is an apocalyptic number.

21451122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21451122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30930480).

21451122 is an abundant number, since it is smaller than the sum of its proper divisors (40409838).

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

21451122 is a wasteful number, since it uses less digits than its factorization.

21451122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 90 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21451122 is about 4631.5355984814. The cubic root of 21451122 is about 277.8540113017.

Adding to 21451122 its reverse (22115412), we get a palindrome (43566534).

The spelling of 21451122 in words is "twenty-one million, four hundred fifty-one thousand, one hundred twenty-two".