261888847643 has 16 divisors (see below), whose sum is σ = 266306019840. Its totient is φ = 257503003296.

The previous prime is 261888847639. The next prime is 261888847669. The reversal of 261888847643 is 346748888162.

It is a cyclic number.

It is not a de Polignac number, because 261888847643 - 2² = 261888847639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261888847643.

It is not an unprimeable number, because it can be changed into a prime (261888840643) 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, 53696321 + ... + 53701197.

It is an arithmetic number, because the mean of its divisors is an integer number (16644126240).

Almost surely, 2^261888847643 is an apocalyptic number.

261888847643 is a deficient number, since it is larger than the sum of its proper divisors (4417172197).

261888847643 is a wasteful number, since it uses less digits than its factorization.

261888847643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7906.

The product of its digits is 99090432, while the sum is 65.

The spelling of 261888847643 in words is "two hundred sixty-one billion, eight hundred eighty-eight million, eight hundred forty-seven thousand, six hundred forty-three".