686437749 has 12 divisors (see below), whose sum is σ = 991875456. Its totient is φ = 457461672.

The previous prime is 686437733. The next prime is 686437751. The reversal of 686437749 is 947734686.

It is a happy number.

It is not a de Polignac number, because 686437749 - 2⁴ = 686437733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 686437695 and 686437704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686437709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16462 + ... + 40544.

It is an arithmetic number, because the mean of its divisors is an integer number (82656288).

Almost surely, 2^686437749 is an apocalyptic number.

It is an amenable number.

686437749 is a deficient number, since it is larger than the sum of its proper divisors (305437707).

686437749 is a wasteful number, since it uses less digits than its factorization.

686437749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27256 (or 27253 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 686437749 is about 26199.9570419495. The cubic root of 686437749 is about 882.1322899970.

The spelling of 686437749 in words is "six hundred eighty-six million, four hundred thirty-seven thousand, seven hundred forty-nine".