861308889 has 16 divisors (see below), whose sum is σ = 1315332480. Its totient is φ = 491103360.

The previous prime is 861308873. The next prime is 861308891. The reversal of 861308889 is 988803168.

It is a happy number.

It is not a de Polignac number, because 861308889 - 2⁴ = 861308873 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (861308809) 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 15 ways as a sum of consecutive naturals, for example, 34804 + ... + 54165.

It is an arithmetic number, because the mean of its divisors is an integer number (82208280).

Almost surely, 2^861308889 is an apocalyptic number.

It is an amenable number.

861308889 is a deficient number, since it is larger than the sum of its proper divisors (454023591).

861308889 is a wasteful number, since it uses less digits than its factorization.

861308889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89440.

The product of its (nonzero) digits is 663552, while the sum is 51.

The square root of 861308889 is about 29348.0644847322. The cubic root of 861308889 is about 951.4507433707.

The spelling of 861308889 in words is "eight hundred sixty-one million, three hundred eight thousand, eight hundred eighty-nine".