684142017869 has 2 divisors, whose sum is σ = 684142017870. Its totient is φ = 684142017868.

The previous prime is 684142017809. The next prime is 684142017893. The reversal of 684142017869 is 968710241486.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 436342155844 + 247799862025 = 660562^2 + 497795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684142017869 is a prime.

It is a super-2 number, since 2×684142017869² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684142017809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342071008934 + 342071008935.

It is an arithmetic number, because the mean of its divisors is an integer number (342071008935).

Almost surely, 2^684142017869 is an apocalyptic number.

It is an amenable number.

684142017869 is a deficient number, since it is larger than the sum of its proper divisors (1).

684142017869 is an equidigital number, since it uses as much as digits as its factorization.

684142017869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4644864, while the sum is 56.

The spelling of 684142017869 in words is "six hundred eighty-four billion, one hundred forty-two million, seventeen thousand, eight hundred sixty-nine".