261550977318 has 64 divisors (see below), whose sum is σ = 582491243520. Its totient is φ = 86993872416.

The previous prime is 261550977307. The next prime is 261550977341. The reversal of 261550977318 is 813779055162.

261550977318 is a `hidden beast` number, since 2 + 6 + 1 + 550 + 9 + 7 + 73 + 18 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56402896 + ... + 56407532.

It is an arithmetic number, because the mean of its divisors is an integer number (9101425680).

Almost surely, 2^261550977318 is an apocalyptic number.

261550977318 is an abundant number, since it is smaller than the sum of its proper divisors (320940266202).

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

261550977318 is a wasteful number, since it uses less digits than its factorization.

261550977318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6698 (or 6692 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 54.

The spelling of 261550977318 in words is "two hundred sixty-one billion, five hundred fifty million, nine hundred seventy-seven thousand, three hundred eighteen".