261243178554 has 32 divisors (see below), whose sum is σ = 526692980736. Its totient is φ = 86380197120.

The previous prime is 261243178529. The next prime is 261243178571. The reversal of 261243178554 is 455871342162.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4820134 + ... + 4874030.

It is an arithmetic number, because the mean of its divisors is an integer number (16459155648).

Almost surely, 2^261243178554 is an apocalyptic number.

261243178554 is an abundant number, since it is smaller than the sum of its proper divisors (265449802182).

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

261243178554 is a wasteful number, since it uses less digits than its factorization.

261243178554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60390.

The product of its digits is 1612800, while the sum is 48.

The spelling of 261243178554 in words is "two hundred sixty-one billion, two hundred forty-three million, one hundred seventy-eight thousand, five hundred fifty-four".