21044478 has 32 divisors (see below), whose sum is σ = 51803136.
Its totient is φ = 5550048.
The previous prime is 21044477. The next prime is 21044479. The reversal of 21044478 is 87444012.
It is an interprime number because it is at equal distance from previous prime (21044477) and next prime (21044479).
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (21044473) 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 15 ways as a sum of consecutive naturals, for example, 18726 + ... + 19817.
It is an arithmetic number, because the mean of its divisors is an integer number (1618848).
Almost surely, 221044478 is an apocalyptic number.
21044478 is an abundant number, since it is smaller than the sum of its proper divisors (30758658).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21044478 is a wasteful number, since it uses less digits than its factorization.
21044478 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 38568.
The product of its (nonzero) digits is 7168, while the sum is 30.
The square root of 21044478 is about 4587.4260756987.
The cubic root of 21044478 is about 276.0870603318.
The spelling of 21044478 in words is "twenty-one million, forty-four thousand, four hundred seventy-eight".