21710066 has 16 divisors (see below), whose sum is σ = 37316160. Its totient is φ = 9279600.

The previous prime is 21710057. The next prime is 21710111. The reversal of 21710066 is 66001712.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4016 + ... + 7716.

It is an arithmetic number, because the mean of its divisors is an integer number (2332260).

Almost surely, 2^21710066 is an apocalyptic number.

21710066 is a deficient number, since it is larger than the sum of its proper divisors (15606094).

21710066 is a wasteful number, since it uses less digits than its factorization.

21710066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4129.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21710066 is about 4659.4061853416. The cubic root of 21710066 is about 278.9675668760.

Adding to 21710066 its reverse (66001712), we get a palindrome (87711778).

The spelling of 21710066 in words is "twenty-one million, seven hundred ten thousand, sixty-six".