21704258 has 8 divisors (see below), whose sum is σ = 32577552. Its totient is φ = 10845076.

The previous prime is 21704233. The next prime is 21704261. The reversal of 21704258 is 85240712.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21704258.

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, 2141 + ... + 6927.

It is an arithmetic number, because the mean of its divisors is an integer number (4072194).

Almost surely, 2^21704258 is an apocalyptic number.

21704258 is a deficient number, since it is larger than the sum of its proper divisors (10873294).

21704258 is a wasteful number, since it uses less digits than its factorization.

21704258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7056.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 21704258 is about 4658.7828882660. The cubic root of 21704258 is about 278.9426876620.

The spelling of 21704258 in words is "twenty-one million, seven hundred four thousand, two hundred fifty-eight".