261564324233504 has 24 divisors (see below), whose sum is σ = 514966001680620. Its totient is φ = 130779307933696.

The previous prime is 261564324233467. The next prime is 261564324233507. The reversal of 261564324233504 is 405332423465162.

It can be written as a sum of positive squares in 2 ways, for example, as 255835290501904 + 5729033731600 = 15994852^2 + 2393540^2 .

It is a super-2 number, since 2×261564324233504² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261564324233507) 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 in 3 ways as a sum of consecutive naturals, for example, 87703649 + ... + 90636960.

Almost surely, 2^{261564324233504} is an apocalyptic number.

It is an amenable number.

261564324233504 is a deficient number, since it is larger than the sum of its proper divisors (253401677447116).

261564324233504 is a wasteful number, since it uses less digits than its factorization.

261564324233504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178386452 (or 178386444 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 50.

Adding to 261564324233504 its reverse (405332423465162), we get a palindrome (666896747698666).

The spelling of 261564324233504 in words is "two hundred sixty-one trillion, five hundred sixty-four billion, three hundred twenty-four million, two hundred thirty-three thousand, five hundred four".