686686441 has 12 divisors (see below), whose sum is σ = 820389828. Its totient is φ = 572679072.

The previous prime is 686686397. The next prime is 686686453. The reversal of 686686441 is 144686686.

It can be written as a sum of positive squares in 2 ways, for example, as 567440041 + 119246400 = 23821^2 + 10920^2 .

It is not a de Polignac number, because 686686441 - 2¹³ = 686678249 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686686471) 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 11 ways as a sum of consecutive naturals, for example, 187566 + ... + 191191.

It is an arithmetic number, because the mean of its divisors is an integer number (68365819).

Almost surely, 2^686686441 is an apocalyptic number.

It is an amenable number.

686686441 is a deficient number, since it is larger than the sum of its proper divisors (133703387).

686686441 is a wasteful number, since it uses less digits than its factorization.

686686441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378808 (or 378801 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 49.

The square root of 686686441 is about 26204.7026504786. The cubic root of 686686441 is about 882.2388074275.

The spelling of 686686441 in words is "six hundred eighty-six million, six hundred eighty-six thousand, four hundred forty-one".