261613368553 has 2 divisors, whose sum is σ = 261613368554. Its totient is φ = 261613368552.

The previous prime is 261613368493. The next prime is 261613368593. The reversal of 261613368553 is 355863316162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 261337708944 + 275659609 = 511212^2 + 16603^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261613368553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261613368497 and 261613368506.

It is not a weakly prime, because it can be changed into another prime (261613368593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130806684276 + 130806684277.

It is an arithmetic number, because the mean of its divisors is an integer number (130806684277).

Almost surely, 2^261613368553 is an apocalyptic number.

It is an amenable number.

261613368553 is a deficient number, since it is larger than the sum of its proper divisors (1).

261613368553 is an equidigital number, since it uses as much as digits as its factorization.

261613368553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2332800, while the sum is 49.

The spelling of 261613368553 in words is "two hundred sixty-one billion, six hundred thirteen million, three hundred sixty-eight thousand, five hundred fifty-three".