261544466217042 has 12 divisors (see below), whose sum is σ = 566679676803630. Its totient is φ = 87181488739008.

The previous prime is 261544466217011. The next prime is 261544466217179. The reversal of 261544466217042 is 240712664445162.

261544466217042 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 4 + 4 + 4 + 6 + 621 + 7 + 0 + 4 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 206301830230521 + 55242635986521 = 14363211^2 + 7432539^2 .

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 261544466217042.

It is an unprimeable number.

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 in 5 ways as a sum of consecutive naturals, for example, 7265124061567 + ... + 7265124061602.

Almost surely, 2^{261544466217042} is an apocalyptic number.

261544466217042 is an abundant number, since it is smaller than the sum of its proper divisors (305135210586588).

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

261544466217042 is a wasteful number, since it uses less digits than its factorization.

261544466217042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14530248123177 (or 14530248123174 counting only the distinct ones).

The product of its (nonzero) digits is 15482880, while the sum is 54.

The spelling of 261544466217042 in words is "two hundred sixty-one trillion, five hundred forty-four billion, four hundred sixty-six million, two hundred seventeen thousand, forty-two".