686644179425 has 6 divisors (see below), whose sum is σ = 851438782518. Its totient is φ = 549315343520.

The previous prime is 686644179373. The next prime is 686644179439. The reversal of 686644179425 is 524971446686.

It can be written as a sum of positive squares in 3 ways, for example, as 346257664 + 686297921761 = 18608^2 + 828431^2 .

It is not a de Polignac number, because 686644179425 - 2¹⁶ = 686644113889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13732883564 + ... + 13732883613.

It is an arithmetic number, because the mean of its divisors is an integer number (141906463753).

Almost surely, 2^686644179425 is an apocalyptic number.

It is an amenable number.

686644179425 is a deficient number, since it is larger than the sum of its proper divisors (164794603093).

686644179425 is a wasteful number, since it uses less digits than its factorization.

686644179425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27465767187 (or 27465767182 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 62.

The spelling of 686644179425 in words is "six hundred eighty-six billion, six hundred forty-four million, one hundred seventy-nine thousand, four hundred twenty-five".