686206121 has 4 divisors (see below), whose sum is σ = 692501700. Its totient is φ = 679910544.

The previous prime is 686206099. The next prime is 686206133. The reversal of 686206121 is 121602686.

686206121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 446730496 + 239475625 = 21136^2 + 15475^2 .

It is a cyclic number.

It is not a de Polignac number, because 686206121 - 2¹⁰ = 686205097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (686206021) 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, 3147626 + ... + 3147843.

It is an arithmetic number, because the mean of its divisors is an integer number (173125425).

Almost surely, 2^686206121 is an apocalyptic number.

It is an amenable number.

686206121 is a deficient number, since it is larger than the sum of its proper divisors (6295579).

686206121 is a wasteful number, since it uses less digits than its factorization.

686206121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6295578.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 686206121 is about 26195.5362800612. The cubic root of 686206121 is about 882.0330581172.

The spelling of 686206121 in words is "six hundred eighty-six million, two hundred six thousand, one hundred twenty-one".