661331052611 has 2 divisors, whose sum is σ = 661331052612. Its totient is φ = 661331052610.

The previous prime is 661331052553. The next prime is 661331052637. The reversal of 661331052611 is 116250133166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661331052611 - 2³⁸ = 386453145667 is a prime.

It is a super-2 number, since 2×661331052611² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661331052691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330665526305 + 330665526306.

It is an arithmetic number, because the mean of its divisors is an integer number (330665526306).

Almost surely, 2^661331052611 is an apocalyptic number.

661331052611 is a deficient number, since it is larger than the sum of its proper divisors (1).

661331052611 is an equidigital number, since it uses as much as digits as its factorization.

661331052611 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

Adding to 661331052611 its reverse (116250133166), we get a palindrome (777581185777).

The spelling of 661331052611 in words is "six hundred sixty-one billion, three hundred thirty-one million, fifty-two thousand, six hundred eleven".