861609511 has 8 divisors (see below), whose sum is σ = 1036522880. Its totient is φ = 699652728.

The previous prime is 861609493. The next prime is 861609559. The reversal of 861609511 is 115906168.

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 861609511 - 2⁵ = 861609479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861609611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3239001 + ... + 3239266.

It is an arithmetic number, because the mean of its divisors is an integer number (129565360).

Almost surely, 2^861609511 is an apocalyptic number.

861609511 is a deficient number, since it is larger than the sum of its proper divisors (174913369).

861609511 is a wasteful number, since it uses less digits than its factorization.

861609511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6478293.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 861609511 is about 29353.1857044512. The cubic root of 861609511 is about 951.5614252094.

The spelling of 861609511 in words is "eight hundred sixty-one million, six hundred nine thousand, five hundred eleven".