21224346 has 64 divisors (see below), whose sum is σ = 51649920. Its totient is φ = 5725440.

The previous prime is 21224323. The next prime is 21224351. The reversal of 21224346 is 64342212.

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, 24456 + ... + 25308.

It is an arithmetic number, because the mean of its divisors is an integer number (807030).

Almost surely, 2^21224346 is an apocalyptic number.

21224346 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21224346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25824960).

21224346 is an abundant number, since it is smaller than the sum of its proper divisors (30425574).

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

21224346 is a wasteful number, since it uses less digits than its factorization.

21224346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911.

The product of its digits is 2304, while the sum is 24.

The square root of 21224346 is about 4606.9888213452. The cubic root of 21224346 is about 276.8714056845.

Adding to 21224346 its reverse (64342212), we get a palindrome (85566558).

The spelling of 21224346 in words is "twenty-one million, two hundred twenty-four thousand, three hundred forty-six".