21404104 has 16 divisors (see below), whose sum is σ = 40359600. Its totient is φ = 10641552.

The previous prime is 21404101. The next prime is 21404147. The reversal of 21404104 is 40140412.

It is not an unprimeable number, because it can be changed into a prime (21404101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6042 + ... + 8905.

It is an arithmetic number, because the mean of its divisors is an integer number (2522475).

Almost surely, 2^21404104 is an apocalyptic number.

It is an amenable number.

21404104 is a deficient number, since it is larger than the sum of its proper divisors (18955496).

21404104 is a wasteful number, since it uses less digits than its factorization.

21404104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15132 (or 15128 counting only the distinct ones).

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

The square root of 21404104 is about 4626.4569597047. The cubic root of 21404104 is about 277.6508564816.

Adding to 21404104 its reverse (40140412), we get a palindrome (61544516).

The spelling of 21404104 in words is "twenty-one million, four hundred four thousand, one hundred four".