21084763 has 4 divisors (see below), whose sum is σ = 24096880. Its totient is φ = 18072648.

The previous prime is 21084751. The next prime is 21084773. The reversal of 21084763 is 36748012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21084763 - 2²¹ = 18987611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21084733) 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 3 ways as a sum of consecutive naturals, for example, 1506048 + ... + 1506061.

It is an arithmetic number, because the mean of its divisors is an integer number (6024220).

Almost surely, 2^21084763 is an apocalyptic number.

21084763 is a deficient number, since it is larger than the sum of its proper divisors (3012117).

21084763 is an equidigital number, since it uses as much as digits as its factorization.

21084763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3012116.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21084763 is about 4591.8147828500. The cubic root of 21084763 is about 276.2631172494.

The spelling of 21084763 in words is "twenty-one million, eighty-four thousand, seven hundred sixty-three".