21716785266 has 16 divisors (see below), whose sum is σ = 47382077088. Its totient is φ = 6580844000.

The previous prime is 21716785199. The next prime is 21716785301. The reversal of 21716785266 is 66258761712.

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, 164521035 + ... + 164521166.

It is an arithmetic number, because the mean of its divisors is an integer number (2961379818).

Almost surely, 2^21716785266 is an apocalyptic number.

21716785266 is an abundant number, since it is smaller than the sum of its proper divisors (25665291822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21716785266 is a wasteful number, since it uses less digits than its factorization.

21716785266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329042217.

The product of its digits is 1693440, while the sum is 51.

The spelling of 21716785266 in words is "twenty-one billion, seven hundred sixteen million, seven hundred eighty-five thousand, two hundred sixty-six".