261799705643 has 8 divisors (see below), whose sum is σ = 302804479488. Its totient is φ = 221696135784.

The previous prime is 261799705639. The next prime is 261799705649. The reversal of 261799705643 is 346507997162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261799705643 - 2² = 261799705639 is a prime.

It is a super-2 number, since 2×261799705643² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261799705649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225300371 + ... + 225301532.

It is an arithmetic number, because the mean of its divisors is an integer number (37850559936).

Almost surely, 2^261799705643 is an apocalyptic number.

261799705643 is a deficient number, since it is larger than the sum of its proper divisors (41004773845).

261799705643 is an equidigital number, since it uses as much as digits as its factorization.

261799705643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450601993.

The product of its (nonzero) digits is 17146080, while the sum is 59.

The spelling of 261799705643 in words is "two hundred sixty-one billion, seven hundred ninety-nine million, seven hundred five thousand, six hundred forty-three".