21707651216 has 10 divisors (see below), whose sum is σ = 42058574262. Its totient is φ = 10853825600.

The previous prime is 21707651201. The next prime is 21707651219. The reversal of 21707651216 is 61215670712.

It can be written as a sum of positive squares in only one way, i.e., 12792514816 + 8915136400 = 113104^2 + 94420^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21707651216.

It is not an unprimeable number, because it can be changed into a prime (21707651219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 678364085 + ... + 678364116.

Almost surely, 2^21707651216 is an apocalyptic number.

It is an amenable number.

21707651216 is a deficient number, since it is larger than the sum of its proper divisors (20350923046).

21707651216 is a wasteful number, since it uses less digits than its factorization.

21707651216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356728209 (or 1356728203 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 38.

The spelling of 21707651216 in words is "twenty-one billion, seven hundred seven million, six hundred fifty-one thousand, two hundred sixteen".