686943681 has 8 divisors (see below), whose sum is σ = 935412864. Its totient is φ = 448218480.

The previous prime is 686943671. The next prime is 686943683. The reversal of 686943681 is 186349686.

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

It is not a de Polignac number, because 686943681 - 2¹⁰ = 686942657 is a prime.

It is a super-2 number, since 2×686943681² = 943783241731659522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (686943683) 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, 2435830 + ... + 2436111.

It is an arithmetic number, because the mean of its divisors is an integer number (116926608).

Almost surely, 2^686943681 is an apocalyptic number.

It is an amenable number.

686943681 is a deficient number, since it is larger than the sum of its proper divisors (248469183).

686943681 is a wasteful number, since it uses less digits than its factorization.

686943681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4871991.

The product of its digits is 1492992, while the sum is 51.

The square root of 686943681 is about 26209.6104702073. The cubic root of 686943681 is about 882.3489590019.

The spelling of 686943681 in words is "six hundred eighty-six million, nine hundred forty-three thousand, six hundred eighty-one".