261615278911 has 16 divisors (see below), whose sum is σ = 303457305600. Its totient is φ = 220903177248.

The previous prime is 261615278887. The next prime is 261615278927. The reversal of 261615278911 is 119872516162.

It is a cyclic number.

It is not a de Polignac number, because 261615278911 - 2¹¹ = 261615276863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261615078911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 288976 + ... + 778933.

It is an arithmetic number, because the mean of its divisors is an integer number (18966081600).

Almost surely, 2^261615278911 is an apocalyptic number.

261615278911 is a deficient number, since it is larger than the sum of its proper divisors (41842026689).

261615278911 is a wasteful number, since it uses less digits than its factorization.

261615278911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1068438.

The product of its digits is 362880, while the sum is 49.

The spelling of 261615278911 in words is "two hundred sixty-one billion, six hundred fifteen million, two hundred seventy-eight thousand, nine hundred eleven".