21041404 has 12 divisors (see below), whose sum is σ = 36855000. Its totient is φ = 10511408.

The previous prime is 21041387. The next prime is 21041407. The reversal of 21041404 is 40414012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21041407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6447 + ... + 9145.

It is an arithmetic number, because the mean of its divisors is an integer number (3071250).

Almost surely, 2^21041404 is an apocalyptic number.

It is an amenable number.

21041404 is a deficient number, since it is larger than the sum of its proper divisors (15813596).

21041404 is a wasteful number, since it uses less digits than its factorization.

21041404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4652 (or 4650 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21041404 is about 4587.0910171916. The cubic root of 21041404 is about 276.0736168535.

Adding to 21041404 its reverse (40414012), we get a palindrome (61455416).

It can be divided in two parts, 210 and 41404, that added together give a palindrome (41614).

The spelling of 21041404 in words is "twenty-one million, forty-one thousand, four hundred four".