686729661 has 8 divisors (see below), whose sum is σ = 916704000. Its totient is φ = 457287552.

The previous prime is 686729647. The next prime is 686729663. The reversal of 686729661 is 166927686.

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

It is not a de Polignac number, because 686729661 - 2⁵ = 686729629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686729663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130036 + ... + 135213.

It is an arithmetic number, because the mean of its divisors is an integer number (114588000).

Almost surely, 2^686729661 is an apocalyptic number.

It is an amenable number.

686729661 is a deficient number, since it is larger than the sum of its proper divisors (229974339).

686729661 is a wasteful number, since it uses less digits than its factorization.

686729661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266115.

The product of its digits is 1306368, while the sum is 51.

The square root of 686729661 is about 26205.5272986445. The cubic root of 686729661 is about 882.2573163903.

The spelling of 686729661 in words is "six hundred eighty-six million, seven hundred twenty-nine thousand, six hundred sixty-one".