611516101661 has 2 divisors, whose sum is σ = 611516101662. Its totient is φ = 611516101660.

The previous prime is 611516101649. The next prime is 611516101663. The reversal of 611516101661 is 166101615116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 452868432025 + 158647669636 = 672955^2 + 398306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-611516101661 is a prime.

Together with 611516101663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (611516101663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305758050830 + 305758050831.

It is an arithmetic number, because the mean of its divisors is an integer number (305758050831).

Almost surely, 2^611516101661 is an apocalyptic number.

It is an amenable number.

611516101661 is a deficient number, since it is larger than the sum of its proper divisors (1).

611516101661 is an equidigital number, since it uses as much as digits as its factorization.

611516101661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 35.

Adding to 611516101661 its reverse (166101615116), we get a palindrome (777617716777).

The spelling of 611516101661 in words is "six hundred eleven billion, five hundred sixteen million, one hundred one thousand, six hundred sixty-one".