686843137600 has 63 divisors (see below), whose sum is σ = 1690144970097. Its totient is φ = 274723994880.

The previous prime is 686843137597. The next prime is 686843137649. The reversal of 686843137600 is 6731348686.

It is a happy number.

The square root of 686843137600 is 828760.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 247263529536 + 439579608064 = 497256^2 + 663008^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 33140041 + ... + 33160759.

Almost surely, 2^686843137600 is an apocalyptic number.

686843137600 is the 828760-th square number.

It is an amenable number.

686843137600 is an abundant number, since it is smaller than the sum of its proper divisors (1003301832497).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686843137600 is an frugal number, since it uses more digits than its factorization.

686843137600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41460 (or 20726 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 52.

The spelling of 686843137600 in words is "six hundred eighty-six billion, eight hundred forty-three million, one hundred thirty-seven thousand, six hundred".