21223004 has 36 divisors (see below), whose sum is σ = 43065960. Its totient is φ = 9073920.

The previous prime is 21222979. The next prime is 21223009. The reversal of 21223004 is 40032212.

It is a self number, because there is not a number n which added to its sum of digits gives 21223004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11882 + ... + 13550.

Almost surely, 2^21223004 is an apocalyptic number.

It is an amenable number.

21223004 is an abundant number, since it is smaller than the sum of its proper divisors (21842956).

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

21223004 is a wasteful number, since it uses less digits than its factorization.

21223004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718 (or 1699 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21223004 is about 4606.8431707624. The cubic root of 21223004 is about 276.8655701021.

Adding to 21223004 its reverse (40032212), we get a palindrome (61255216).

The spelling of 21223004 in words is "twenty-one million, two hundred twenty-three thousand, four".