686986989 has 8 divisors (see below), whose sum is σ = 986442912. Its totient is φ = 422761200.

The previous prime is 686986981. The next prime is 686986991. The reversal of 686986989 is 989689686.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 686986989 - 2³ = 686986981 is a prime.

It is a super-2 number, since 2×686986989² = 943902246110572242, which contains 22 as substring.

686986989 is a strobogrammatic number because it is the same when read upside-down.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686986981) 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, 8807487 + ... + 8807564.

It is an arithmetic number, because the mean of its divisors is an integer number (123305364).

Almost surely, 2^686986989 is an apocalyptic number.

It is an amenable number.

686986989 is a deficient number, since it is larger than the sum of its proper divisors (299455923).

686986989 is a wasteful number, since it uses less digits than its factorization.

686986989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17615067.

The product of its digits is 80621568, while the sum is 69.

The square root of 686986989 is about 26210.4366426811. The cubic root of 686986989 is about 882.3675010196.

The spelling of 686986989 in words is "six hundred eighty-six million, nine hundred eighty-six thousand, nine hundred eighty-nine".