21404396 has 24 divisors (see below), whose sum is σ = 40466160. Its totient is φ = 9847872.

The previous prime is 21404371. The next prime is 21404399. The reversal of 21404396 is 69340412.

It is not an unprimeable number, because it can be changed into a prime (21404399) 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 7 ways as a sum of consecutive naturals, for example, 28595 + ... + 29333.

It is an arithmetic number, because the mean of its divisors is an integer number (1686090).

Almost surely, 2^21404396 is an apocalyptic number.

21404396 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21404396 is a deficient number, since it is larger than the sum of its proper divisors (19061764).

21404396 is a wasteful number, since it uses less digits than its factorization.

21404396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313 (or 1311 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21404396 is about 4626.4885172234. The cubic root of 21404396 is about 277.6521190694.

The spelling of 21404396 in words is "twenty-one million, four hundred four thousand, three hundred ninety-six".