581005866661 has 16 divisors (see below), whose sum is σ = 655824784896. Its totient is φ = 509934600000.

The previous prime is 581005866643. The next prime is 581005866709. The reversal of 581005866661 is 166668500185.

It is a cyclic number.

It is not a de Polignac number, because 581005866661 - 2⁵ = 581005866629 is a prime.

It is a super-2 number, since 2×581005866661² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 581005866599 and 581005866608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (581005866461) 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, 1879990 + ... + 2167111.

It is an arithmetic number, because the mean of its divisors is an integer number (40989049056).

Almost surely, 2^581005866661 is an apocalyptic number.

It is an amenable number.

581005866661 is a deficient number, since it is larger than the sum of its proper divisors (74818918235).

581005866661 is a wasteful number, since it uses less digits than its factorization.

581005866661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4047564.

The product of its (nonzero) digits is 2073600, while the sum is 52.

The spelling of 581005866661 in words is "five hundred eighty-one billion, five million, eight hundred sixty-six thousand, six hundred sixty-one".