685667551 has 8 divisors (see below), whose sum is σ = 702732800. Its totient is φ = 668653272.

The previous prime is 685667533. The next prime is 685667569. The reversal of 685667551 is 155766586.

It is an interprime number because it is at equal distance from previous prime (685667533) and next prime (685667569).

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

It is a cyclic number.

It is not a de Polignac number, because 685667551 - 2¹⁵ = 685634783 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 685667495 and 685667504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685667501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15250 + ... + 40048.

It is an arithmetic number, because the mean of its divisors is an integer number (87841600).

Almost surely, 2^685667551 is an apocalyptic number.

685667551 is a deficient number, since it is larger than the sum of its proper divisors (17065249).

685667551 is a wasteful number, since it uses less digits than its factorization.

685667551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25485.

The product of its digits is 1512000, while the sum is 49.

The square root of 685667551 is about 26185.2544574232. The cubic root of 685667551 is about 881.8022426904.

The spelling of 685667551 in words is "six hundred eighty-five million, six hundred sixty-seven thousand, five hundred fifty-one".