261544020733544 has 64 divisors (see below), whose sum is σ = 512144378052480. Its totient is φ = 124981705728000.

The previous prime is 261544020733511. The next prime is 261544020733549. The reversal of 261544020733544 is 445337020445162.

It is a happy number.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 261544020733492 and 261544020733501.

It is not an unprimeable number, because it can be changed into a prime (261544020733549) 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 15 ways as a sum of consecutive naturals, for example, 6499421264 + ... + 6499461504.

It is an arithmetic number, because the mean of its divisors is an integer number (8002255907070).

Almost surely, 2^{261544020733544} is an apocalyptic number.

It is an amenable number.

261544020733544 is a deficient number, since it is larger than the sum of its proper divisors (250600357318936).

261544020733544 is a wasteful number, since it uses less digits than its factorization.

261544020733544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68922 (or 68918 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 50.

The spelling of 261544020733544 in words is "two hundred sixty-one trillion, five hundred forty-four billion, twenty million, seven hundred thirty-three thousand, five hundred forty-four".