661220053633 has 2 divisors, whose sum is σ = 661220053634. Its totient is φ = 661220053632.

The previous prime is 661220053597. The next prime is 661220053661. The reversal of 661220053633 is 336350022166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 658772475904 + 2447577729 = 811648^2 + 49473^2 .

It is a cyclic number.

It is not a de Polignac number, because 661220053633 - 2⁹ = 661220053121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661220053592 and 661220053601.

It is not a weakly prime, because it can be changed into another prime (661220053033) 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, 330610026816 + 330610026817.

It is an arithmetic number, because the mean of its divisors is an integer number (330610026817).

Almost surely, 2^661220053633 is an apocalyptic number.

It is an amenable number.

661220053633 is a deficient number, since it is larger than the sum of its proper divisors (1).

661220053633 is an equidigital number, since it uses as much as digits as its factorization.

661220053633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 37.

Adding to 661220053633 its reverse (336350022166), we get a palindrome (997570075799).

The spelling of 661220053633 in words is "six hundred sixty-one billion, two hundred twenty million, fifty-three thousand, six hundred thirty-three".