21568082216 has 16 divisors (see below), whose sum is σ = 40446861300. Its totient is φ = 10782252544.

The previous prime is 21568082203. The next prime is 21568082227. The reversal of 21568082216 is 61228086512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21475730116 + 92352100 = 146546^2 + 9610^2 .

It is a super-2 number, since 2×21568082216² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171611 + ... + 269418.

Almost surely, 2^21568082216 is an apocalyptic number.

It is an amenable number.

21568082216 is a deficient number, since it is larger than the sum of its proper divisors (18878779084).

21568082216 is a wasteful number, since it uses less digits than its factorization.

21568082216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447148 (or 447144 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 21568082216 in words is "twenty-one billion, five hundred sixty-eight million, eighty-two thousand, two hundred sixteen".