21084442 has 8 divisors (see below), whose sum is σ = 31670100. Its totient is φ = 10527744.

The previous prime is 21084419. The next prime is 21084451. The reversal of 21084442 is 24448012.

It can be written as a sum of positive squares in 2 ways, for example, as 20620681 + 463761 = 4541^2 + 681^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 5317 + ... + 8392.

Almost surely, 2^21084442 is an apocalyptic number.

21084442 is a deficient number, since it is larger than the sum of its proper divisors (10585658).

21084442 is a wasteful number, since it uses less digits than its factorization.

21084442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14480.

The product of its (nonzero) digits is 2048, while the sum is 25.

The square root of 21084442 is about 4591.7798292166. The cubic root of 21084442 is about 276.2617152748.

The spelling of 21084442 in words is "twenty-one million, eighty-four thousand, four hundred forty-two".