261003581568 has 96 divisors (see below), whose sum is σ = 759504224700. Its totient is φ = 86023618560.

The previous prime is 261003581567. The next prime is 261003581633. The reversal of 261003581568 is 865185300162.

261003581568 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 0 + 3 + 5 + 81 + 568 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 255057321024 + 5946260544 = 505032^2 + 77112^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (261003581567) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1170313 + ... + 1375368.

Almost surely, 2^261003581568 is an apocalyptic number.

It is an amenable number.

261003581568 is an abundant number, since it is smaller than the sum of its proper divisors (498500643132).

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

261003581568 is a wasteful number, since it uses less digits than its factorization.

261003581568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2545790 (or 2545775 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 261003581568 in words is "two hundred sixty-one billion, three million, five hundred eighty-one thousand, five hundred sixty-eight".