261563351262063 has 4 divisors (see below), whose sum is σ = 348751135016088. Its totient is φ = 174375567508040.

The previous prime is 261563351262019. The next prime is 261563351262071. The reversal of 261563351262063 is 360262153365162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261563351262063 - 2⁶ = 261563351261999 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261563351261997 and 261563351262015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261563351263063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43593891877008 + ... + 43593891877013.

It is an arithmetic number, because the mean of its divisors is an integer number (87187783754022).

Almost surely, 2^{261563351262063} is an apocalyptic number.

261563351262063 is a deficient number, since it is larger than the sum of its proper divisors (87187783754025).

261563351262063 is an equidigital number, since it uses as much as digits as its factorization.

261563351262063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87187783754024.

The product of its (nonzero) digits is 6998400, while the sum is 51.

The spelling of 261563351262063 in words is "two hundred sixty-one trillion, five hundred sixty-three billion, three hundred fifty-one million, two hundred sixty-two thousand, sixty-three".