21230404 has 24 divisors (see below), whose sum is σ = 40501440. Its totient is φ = 9678624.

The previous prime is 21230401. The next prime is 21230431. The reversal of 21230404 is 40403212.

It is not an unprimeable number, because it can be changed into a prime (21230401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1857 + ... + 6775.

It is an arithmetic number, because the mean of its divisors is an integer number (1687560).

Almost surely, 2^21230404 is an apocalyptic number.

It is an amenable number.

21230404 is a deficient number, since it is larger than the sum of its proper divisors (19271036).

21230404 is a wasteful number, since it uses less digits than its factorization.

21230404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5019 (or 5017 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21230404 is about 4607.6462537829. The cubic root of 21230404 is about 276.8977453641.

Adding to 21230404 its reverse (40403212), we get a palindrome (61633616).

The spelling of 21230404 in words is "twenty-one million, two hundred thirty thousand, four hundred four".