686741378969 has 2 divisors, whose sum is σ = 686741378970. Its totient is φ = 686741378968.

The previous prime is 686741378963. The next prime is 686741379001. The reversal of 686741378969 is 969873147686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 535952839744 + 150788539225 = 732088^2 + 388315^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686741378969 is a prime.

It is a super-2 number, since 2×686741378969² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 686741378896 and 686741378905.

It is not a weakly prime, because it can be changed into another prime (686741378963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343370689484 + 343370689485.

It is an arithmetic number, because the mean of its divisors is an integer number (343370689485).

Almost surely, 2^686741378969 is an apocalyptic number.

It is an amenable number.

686741378969 is a deficient number, since it is larger than the sum of its proper divisors (1).

686741378969 is an equidigital number, since it uses as much as digits as its factorization.

686741378969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 658409472, while the sum is 74.

The spelling of 686741378969 in words is "six hundred eighty-six billion, seven hundred forty-one million, three hundred seventy-eight thousand, nine hundred sixty-nine".