684410398681 has 9 divisors (see below), whose sum is σ = 691338233919. Its totient is φ = 677551329000.

The previous prime is 684410398669. The next prime is 684410398729. The reversal of 684410398681 is 186893014486.

The square root of 684410398681 is 827291.

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., 657573406281 + 26836992400 = 810909^2 + 163820^2 .

It is not a de Polignac number, because 684410398681 - 2¹⁷ = 684410267609 is a prime.

It is a super-2 number, since 2×684410398681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684410398381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 83552296 + ... + 83560486.

Almost surely, 2^684410398681 is an apocalyptic number.

684410398681 is the 827291-st square number.

684410398681 is the 413646-th centered octagonal number.

It is an amenable number.

684410398681 is a deficient number, since it is larger than the sum of its proper divisors (6927835238).

684410398681 is an frugal number, since it uses more digits than its factorization.

684410398681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16584 (or 8292 counting only the distinct ones).

The product of its (nonzero) digits is 7962624, while the sum is 58.

The spelling of 684410398681 in words is "six hundred eighty-four billion, four hundred ten million, three hundred ninety-eight thousand, six hundred eighty-one".