861017859511 has 4 divisors (see below), whose sum is σ = 911665968912. Its totient is φ = 810369750112.

The previous prime is 861017859509. The next prime is 861017859517. The reversal of 861017859511 is 115958710168.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 861017859511 - 2¹ = 861017859509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861017859517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25324054675 + ... + 25324054708.

It is an arithmetic number, because the mean of its divisors is an integer number (227916492228).

Almost surely, 2^861017859511 is an apocalyptic number.

861017859511 is a deficient number, since it is larger than the sum of its proper divisors (50648109401).

861017859511 is a wasteful number, since it uses less digits than its factorization.

861017859511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50648109400.

The product of its (nonzero) digits is 604800, while the sum is 52.

The spelling of 861017859511 in words is "eight hundred sixty-one billion, seventeen million, eight hundred fifty-nine thousand, five hundred eleven".