21244433 has 16 divisors (see below), whose sum is σ = 25559040. Its totient is φ = 17264016.

The previous prime is 21244417. The next prime is 21244459. The reversal of 21244433 is 33444212.

It is not a de Polignac number, because 21244433 - 2⁴ = 21244417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21244399 and 21244408.

It is not an unprimeable number, because it can be changed into a prime (21244463) 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, 19928 + ... + 20966.

It is an arithmetic number, because the mean of its divisors is an integer number (1597440).

Almost surely, 2^21244433 is an apocalyptic number.

21244433 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21244433 is a deficient number, since it is larger than the sum of its proper divisors (4314607).

21244433 is a wasteful number, since it uses less digits than its factorization.

21244433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1196.

The product of its digits is 2304, while the sum is 23.

The square root of 21244433 is about 4609.1683631649. The cubic root of 21244433 is about 276.9587230566.

Adding to 21244433 its reverse (33444212), we get a palindrome (54688645).

The spelling of 21244433 in words is "twenty-one million, two hundred forty-four thousand, four hundred thirty-three".