616612261 has 2 divisors, whose sum is σ = 616612262. Its totient is φ = 616612260.

The previous prime is 616612259. The next prime is 616612279. The reversal of 616612261 is 162216616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 559322500 + 57289761 = 23650^2 + 7569^2 .

It is a cyclic number.

It is not a de Polignac number, because 616612261 - 2¹ = 616612259 is a prime.

Together with 616612259, 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 (616612231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308306130 + 308306131.

It is an arithmetic number, because the mean of its divisors is an integer number (308306131).

Almost surely, 2^616612261 is an apocalyptic number.

It is an amenable number.

616612261 is a deficient number, since it is larger than the sum of its proper divisors (1).

616612261 is an equidigital number, since it uses as much as digits as its factorization.

616612261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 31.

The square root of 616612261 is about 24831.6785779778. The cubic root of 616612261 is about 851.1459795427.

Adding to 616612261 its reverse (162216616), we get a palindrome (778828877).

The spelling of 616612261 in words is "six hundred sixteen million, six hundred twelve thousand, two hundred sixty-one".