261544423371756 has 24 divisors (see below), whose sum is σ = 697451795658240. Its totient is φ = 74726978106192.

The previous prime is 261544423371743. The next prime is 261544423371757. The reversal of 261544423371756 is 657173324445162.

It is a self number, because there is not a number n which added to its sum of digits gives 261544423371756.

It is not an unprimeable number, because it can be changed into a prime (261544423371757) 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 7 ways as a sum of consecutive naturals, for example, 1556812043796 + ... + 1556812043963.

It is an arithmetic number, because the mean of its divisors is an integer number (29060491485760).

Almost surely, 2^{261544423371756} is an apocalyptic number.

It is an amenable number.

261544423371756 is an abundant number, since it is smaller than the sum of its proper divisors (435907372286484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261544423371756 is a wasteful number, since it uses less digits than its factorization.

261544423371756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3113624087773 (or 3113624087771 counting only the distinct ones).

The product of its digits is 101606400, while the sum is 60.

The spelling of 261544423371756 in words is "two hundred sixty-one trillion, five hundred forty-four billion, four hundred twenty-three million, three hundred seventy-one thousand, seven hundred fifty-six".