216821540882 has 16 divisors (see below), whose sum is σ = 336992569560. Its totient is φ = 104502803328.

The previous prime is 216821540861. The next prime is 216821540909. The reversal of 216821540882 is 288045128612.

It is a Cunningham number, because it is equal to 465641²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 113696421721 + 103125119161 = 337189^2 + 321131^2 .

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, 2993633 + ... + 3065204.

Almost surely, 2^216821540882 is an apocalyptic number.

216821540882 is a deficient number, since it is larger than the sum of its proper divisors (120171028678).

216821540882 is a wasteful number, since it uses less digits than its factorization.

216821540882 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6059485.

The product of its (nonzero) digits is 491520, while the sum is 47.

The spelling of 216821540882 in words is "two hundred sixteen billion, eight hundred twenty-one million, five hundred forty thousand, eight hundred eighty-two".