261106395264 has 1920 divisors, whose sum is σ = 1040756428800. Its totient is φ = 64049356800.

The previous prime is 261106395247. The next prime is 261106395271. The reversal of 261106395264 is 462593601162.

261106395264 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 0 + 639 + 5 + 2 + 6 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 8422786929 + ... + 8422786959.

It is an arithmetic number, because the mean of its divisors is an integer number (542060640).

Almost surely, 2^261106395264 is an apocalyptic number.

261106395264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261106395264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (520378214400).

261106395264 is an abundant number, since it is smaller than the sum of its proper divisors (779650033536).

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

261106395264 is a wasteful number, since it uses less digits than its factorization.

261106395264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 261106395264 in words is "two hundred sixty-one billion, one hundred six million, three hundred ninety-five thousand, two hundred sixty-four".