21404494 has 16 divisors (see below), whose sum is σ = 33534000. Its totient is φ = 10233664.

The previous prime is 21404491. The next prime is 21404503. The reversal of 21404494 is 49440412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404491) 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, 4482 + ... + 7930.

It is an arithmetic number, because the mean of its divisors is an integer number (2095875).

Almost surely, 2^21404494 is an apocalyptic number.

21404494 is a deficient number, since it is larger than the sum of its proper divisors (12129506).

21404494 is a wasteful number, since it uses less digits than its factorization.

21404494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3587.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 21404494 is about 4626.4991083972. The cubic root of 21404494 is about 277.6525428120.

The spelling of 21404494 in words is "twenty-one million, four hundred four thousand, four hundred ninety-four".