216961781258 has 4 divisors (see below), whose sum is σ = 325442671890. Its totient is φ = 108480890628.

The previous prime is 216961781243. The next prime is 216961781263. The reversal of 216961781258 is 852187169612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 210201159529 + 6760621729 = 458477^2 + 82223^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54240445313 + ... + 54240445316.

Almost surely, 2^216961781258 is an apocalyptic number.

216961781258 is a deficient number, since it is larger than the sum of its proper divisors (108480890632).

216961781258 is a wasteful number, since it uses less digits than its factorization.

216961781258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108480890631.

The product of its digits is 2903040, while the sum is 56.

The spelling of 216961781258 in words is "two hundred sixteen billion, nine hundred sixty-one million, seven hundred eighty-one thousand, two hundred fifty-eight".