261665117270046 has 48 divisors (see below), whose sum is σ = 647949404700000. Its totient is φ = 74759531304384.

The previous prime is 261665117270041. The next prime is 261665117270099. The reversal of 261665117270046 is 640072711566162.

261665117270046 is a `hidden beast` number, since 2 + 6 + 1 + 66 + 511 + 7 + 27 + 0 + 0 + 46 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 261665117269974 and 261665117270001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261665117270041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21914541 + ... + 31679288.

It is an arithmetic number, because the mean of its divisors is an integer number (13498945931250).

Almost surely, 2^{261665117270046} is an apocalyptic number.

261665117270046 is an abundant number, since it is smaller than the sum of its proper divisors (386284287429954).

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

261665117270046 is a wasteful number, since it uses less digits than its factorization.

261665117270046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53632593 (or 53632590 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 261665117270046 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, one hundred seventeen million, two hundred seventy thousand, forty-six".