21704858 has 16 divisors (see below), whose sum is σ = 37407744. Its totient is φ = 9252240.

The previous prime is 21704857. The next prime is 21704887. The reversal of 21704858 is 85840712.

It is a super-2 number, since 2×21704858² = 942201721600328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21704857) 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 7 ways as a sum of consecutive naturals, for example, 1385 + ... + 6732.

It is an arithmetic number, because the mean of its divisors is an integer number (2337984).

Almost surely, 2^21704858 is an apocalyptic number.

21704858 is a deficient number, since it is larger than the sum of its proper divisors (15702886).

21704858 is a wasteful number, since it uses less digits than its factorization.

21704858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8317.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 21704858 is about 4658.8472823221. The cubic root of 21704858 is about 278.9452580343.

The spelling of 21704858 in words is "twenty-one million, seven hundred four thousand, eight hundred fifty-eight".