686540429 has 4 divisors (see below), whose sum is σ = 699494076. Its totient is φ = 673586784.

The previous prime is 686540419. The next prime is 686540431. The reversal of 686540429 is 924045686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 480617929 + 205922500 = 21923^2 + 14350^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686540429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 686540429.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686540419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6476744 + ... + 6476849.

It is an arithmetic number, because the mean of its divisors is an integer number (174873519).

Almost surely, 2^686540429 is an apocalyptic number.

It is an amenable number.

686540429 is a deficient number, since it is larger than the sum of its proper divisors (12953647).

686540429 is a wasteful number, since it uses less digits than its factorization.

686540429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12953646.

The product of its (nonzero) digits is 414720, while the sum is 44.

The square root of 686540429 is about 26201.9165138736. The cubic root of 686540429 is about 882.1762720516.

The spelling of 686540429 in words is "six hundred eighty-six million, five hundred forty thousand, four hundred twenty-nine".