21224434 has 32 divisors (see below), whose sum is σ = 39914496. Its totient is φ = 8223120.

The previous prime is 21224431. The next prime is 21224447. The reversal of 21224434 is 43442212.

It is a happy number.

It is a super-3 number, since 3×21224434³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21224431) 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, 43339 + ... + 43825.

It is an arithmetic number, because the mean of its divisors is an integer number (1247328).

Almost surely, 2^21224434 is an apocalyptic number.

21224434 is a deficient number, since it is larger than the sum of its proper divisors (18690062).

21224434 is a wasteful number, since it uses less digits than its factorization.

21224434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790.

The product of its digits is 1536, while the sum is 22.

The square root of 21224434 is about 4606.9983720423. The cubic root of 21224434 is about 276.8717883370.

Adding to 21224434 its reverse (43442212), we get a palindrome (64666646).

It can be divided in two parts, 2122 and 4434, that added together give a palindrome (6556).

The spelling of 21224434 in words is "twenty-one million, two hundred twenty-four thousand, four hundred thirty-four".