686485889 has 4 divisors (see below), whose sum is σ = 686687700. Its totient is φ = 686284080.

The previous prime is 686485861. The next prime is 686485907. The reversal of 686485889 is 988584686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988584686 = 2 ⋅494292343.

It can be written as a sum of positive squares in 2 ways, for example, as 470542864 + 215943025 = 21692^2 + 14695^2 .

It is a cyclic number.

It is not a de Polignac number, because 686485889 - 2⁸ = 686485633 is a prime.

It is a super-2 number, since 2×686485889² = 942525751592240642, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (686485859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95714 + ... + 102635.

It is an arithmetic number, because the mean of its divisors is an integer number (171671925).

Almost surely, 2^686485889 is an apocalyptic number.

It is an amenable number.

686485889 is a deficient number, since it is larger than the sum of its proper divisors (201811).

686485889 is a wasteful number, since it uses less digits than its factorization.

686485889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201810.

The product of its digits is 26542080, while the sum is 62.

The square root of 686485889 is about 26200.8757296393. The cubic root of 686485889 is about 882.1529108792.

The spelling of 686485889 in words is "six hundred eighty-six million, four hundred eighty-five thousand, eight hundred eighty-nine".