686101561 has 4 divisors (see below), whose sum is σ = 686800512. Its totient is φ = 685402612.

The previous prime is 686101541. The next prime is 686101583. The reversal of 686101561 is 165101686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 686101561 - 2⁷ = 686101433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686101511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 348001 + ... + 349966.

It is an arithmetic number, because the mean of its divisors is an integer number (171700128).

Almost surely, 2^686101561 is an apocalyptic number.

It is an amenable number.

686101561 is a deficient number, since it is larger than the sum of its proper divisors (698951).

686101561 is an equidigital number, since it uses as much as digits as its factorization.

686101561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698950.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 686101561 is about 26193.5404441629. The cubic root of 686101561 is about 881.9882561943.

The spelling of 686101561 in words is "six hundred eighty-six million, one hundred one thousand, five hundred sixty-one".