216502774261 has 2 divisors, whose sum is σ = 216502774262. Its totient is φ = 216502774260.

The previous prime is 216502774259. The next prime is 216502774307. The reversal of 216502774261 is 162477205612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 175372500625 + 41130273636 = 418775^2 + 202806^2 .

It is a cyclic number.

It is not a de Polignac number, because 216502774261 - 2¹ = 216502774259 is a prime.

It is a super-2 number, since 2×216502774261² (a number of 23 digits) contains 22 as substring.

Together with 216502774259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216502474261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108251387130 + 108251387131.

It is an arithmetic number, because the mean of its divisors is an integer number (108251387131).

Almost surely, 2^216502774261 is an apocalyptic number.

It is an amenable number.

216502774261 is a deficient number, since it is larger than the sum of its proper divisors (1).

216502774261 is an equidigital number, since it uses as much as digits as its factorization.

216502774261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 282240, while the sum is 43.

Adding to 216502774261 its reverse (162477205612), we get a palindrome (378979979873).

The spelling of 216502774261 in words is "two hundred sixteen billion, five hundred two million, seven hundred seventy-four thousand, two hundred sixty-one".