861308890 has 16 divisors (see below), whose sum is σ = 1669614408. Its totient is φ = 318021696.

The previous prime is 861308873. The next prime is 861308891. The reversal of 861308890 is 98803168.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 554743809 + 306565081 = 23553^2 + 17509^2 .

It is not an unprimeable number, because it can be changed into a prime (861308891) 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, 3312597 + ... + 3312856.

Almost surely, 2^861308890 is an apocalyptic number.

861308890 is a deficient number, since it is larger than the sum of its proper divisors (808305518).

861308890 is a wasteful number, since it uses less digits than its factorization.

861308890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6625473.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 861308890 is about 29348.0645017691. The cubic root of 861308890 is about 951.4507437389.

The spelling of 861308890 in words is "eight hundred sixty-one million, three hundred eight thousand, eight hundred ninety".