21706606 has 16 divisors (see below), whose sum is σ = 33310368. Its totient is φ = 10605600.

The previous prime is 21706591. The next prime is 21706609. The reversal of 21706606 is 60660712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21591 + ... + 22573.

It is an arithmetic number, because the mean of its divisors is an integer number (2081898).

Almost surely, 2^21706606 is an apocalyptic number.

21706606 is a deficient number, since it is larger than the sum of its proper divisors (11603762).

21706606 is a wasteful number, since it uses less digits than its factorization.

21706606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21706606 is about 4659.0348785988. The cubic root of 21706606 is about 278.9527461156.

The spelling of 21706606 in words is "twenty-one million, seven hundred six thousand, six hundred six".