21704105 has 8 divisors (see below), whose sum is σ = 26472264. Its totient is φ = 17078400.

The previous prime is 21704101. The next prime is 21704107. The reversal of 21704105 is 50140712.

It can be written as a sum of positive squares in 4 ways, for example, as 350464 + 21353641 = 592^2 + 4621^2 .

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

It is not a de Polignac number, because 21704105 - 2² = 21704101 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21704101) 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, 35276 + ... + 35885.

It is an arithmetic number, because the mean of its divisors is an integer number (3309033).

Almost surely, 2^21704105 is an apocalyptic number.

It is an amenable number.

21704105 is a deficient number, since it is larger than the sum of its proper divisors (4768159).

21704105 is an equidigital number, since it uses as much as digits as its factorization.

21704105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71227.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 21704105 is about 4658.7664676393. The cubic root of 21704105 is about 278.9420322095.

Adding to 21704105 its reverse (50140712), we get a palindrome (71844817).

The spelling of 21704105 in words is "twenty-one million, seven hundred four thousand, one hundred five".