864920989 has 4 divisors (see below), whose sum is σ = 869699740. Its totient is φ = 860142240.

The previous prime is 864920981. The next prime is 864921041. The reversal of 864920989 is 989029468.

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

It can be written as a sum of positive squares in 2 ways, for example, as 58644964 + 806276025 = 7658^2 + 28395^2 .

It is a cyclic number.

It is not a de Polignac number, because 864920989 - 2³ = 864920981 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 (864920981) 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 3 ways as a sum of consecutive naturals, for example, 2389104 + ... + 2389465.

It is an arithmetic number, because the mean of its divisors is an integer number (217424935).

Almost surely, 2^864920989 is an apocalyptic number.

It is an amenable number.

864920989 is a deficient number, since it is larger than the sum of its proper divisors (4778751).

864920989 is a wasteful number, since it uses less digits than its factorization.

864920989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4778750.

The product of its (nonzero) digits is 2239488, while the sum is 55.

The square root of 864920989 is about 29409.5390817333. The cubic root of 864920989 is about 952.7789320478.

The spelling of 864920989 in words is "eight hundred sixty-four million, nine hundred twenty thousand, nine hundred eighty-nine".