21082647 has 16 divisors (see below), whose sum is σ = 30096000. Its totient is φ = 13087584.

The previous prime is 21082631. The next prime is 21082667. The reversal of 21082647 is 74628012.

It is not a de Polignac number, because 21082647 - 2⁴ = 21082631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21082627) 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 15 ways as a sum of consecutive naturals, for example, 229 + ... + 6497.

It is an arithmetic number, because the mean of its divisors is an integer number (1881000).

Almost surely, 2^21082647 is an apocalyptic number.

21082647 is a deficient number, since it is larger than the sum of its proper divisors (9013353).

21082647 is a wasteful number, since it uses less digits than its factorization.

21082647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6350.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 21082647 is about 4591.5843670785. The cubic root of 21082647 is about 276.2538753099.

The spelling of 21082647 in words is "twenty-one million, eighty-two thousand, six hundred forty-seven".